2139 cpu
pst...@home.com
changed to install a new cpu in a 2139
Chuck2
The following I saved from the IBM Forum for future use and have upgraded
my 2153 to 550mhz CPU. It also has information for the 2139 all the
information has been tested and works. However, for the latest on 500 and
550 mhz cpus go to the following board and search on 2139 CPU upgrades.
http://novogate.com/cgi-bin/aptiva/Ultimate.cgi
Could anyone re-post the message by Mr. Bob Dixon on 9/8? It's supposed to
be a really excellent guide on CPU upgrade, but it's too late to read it
in the forum.
Thanks,
1. This is PART I of a two-part information posting regarding
Central Processing Unit (CPU) upgrades for the Aptiva 2153/K6,
2153/Celeron, and 2139 motherboards (hereafter referred to as
"system boards"). No IBM technical support is requested;
however, any experience/expertise/input that IBM would allow
their support personnel to contribute would be greatly
appreciated.
a. Paragraphs 2-6 of PART I contain general information about
upgrading the CPU in all of the Aptiva 2139/2153 models.
Paragraph 7 (in PART I) discusses CPU upgrades for the Aptiva
2139; and paragraphs 10 and 11 (IN PART II) pertain to the
2153/K6 and 2153/Celeron models, respectively.
b. Information contained in both parts of this message is based
on my research as well as my experience in upgrading the CPU
in my 2153E2N. This message is a little lengthy in order to
accommodate anyone who may not be that proficient with
concepts and terminology, as well as to save some time for
those who may not be "research-inclined".
2. Unless you are familiar with changing out the CPU and heat
sink/fan unit, I recommend reviewing the Aptiva 2139/2153
Hardware Maintenance Manual (HMM) before installing a new
CPU. The online HMM can be found at the following Internet
Universal Resource Locator (URL) address (i.e., web site):
http://www.pc.ibm.com/us/aptiva/tech_library.html
Click on "Online Publications", then "Hardware Maintenance
Manuals", then "Aptiva - 2139/2153 Hardware Maintenance
Manual (HMM)" - it should be the eighth manual from the top.
[ NOTE 1: In lieu of the HMM, the online schematics for the
2153/K6, 2153/Celeron, and 2139 system boards, together with
their switch settings can be found at the following URLs:
- 2153/K6:
http://servicepac.mainz.ibm.com/eprmhtml/eprmb/f1382.htm
- 2153/Celeron:
http://servicepac.mainz.ibm.com/eprmhtml/eprmb/f1384.htm
- 2139/PII:
http://servicepac.mainz.ibm.com/eprmhtml/eprmb/f1386.htm
[ NOTE 2: The Service/Maintenance/Diagnostic URL for the
Aptiva 2139/2153 is:
http://servicepac.mainz.ibm.com/eprmhtml/eprmb/1387.htm ]
IBM Aptiva system boards and BIOS are manufactured by Acer,
Taiwan. However, as with IBM, Acer will not provide any
technical support for either the system board or BIOS. Also,
since total system board design and construction must be
considered when upgrading, you will not receive any assistance
from component manufactures such as Intel, AMD, Cyrix, and
ATi. Therefore, you're on your own if you want to upgrade
beyond what the HMM indicates.
3. Description of processor removal and installation can be
found in the HMM, Chapter 4:
a. Pages 4-16 through 4-17 for the 2153/K6
- "Processor(K6)"
b. Pages 4-18 through 4-21 for the 2153/Celeron
- "Processor(Celeron)"
c. Pages 4-41 through 4-44 for the 2139
- "Pentium II Processor Module"
[ NOTE 3: The HMM is a .pdf document, so you must have
Adobe Acrobat Reader installed before trying to access the
manual. Also, Windows should be set up to automatically launch
Acrobat Reader when a .pdf file is accessed. The HMM is 8.2 MB
in size, so it will take some time to download before you can
read it, depending on how fast your modem is (about 30 minutes
using a 56K modem). If you don't have access to a high-speed
modem (DSL, cable, ISDN, T1, etc.), I recommend loading it
when internet activity is low, and then immediately saving it to
your hard disk ("Save As" option under the "File" menu) - that
way you can read it off-line at any time. You can download
Acrobat Reader for free from the Adobe web site
(http://www.adobe.com) or through the link provided at the
HMM Internet address listed in the previous paragraph. ]
4. Referring to the HMM, Aptiva model/system board
combinations are as follows:
a. System Board P/N: 20L2161
Machine Type: 2139
Models: E5D, EP4, E6N, E5U, E6U, E6C
Processor: Pentium II (PII)
b. System Board P/N: 00K8747
Machine Type: 2153
Models: E2N, E3N
Processor: K6
c. System Board P/N: 20L2184
Machine Type: 2153
Models: E4N
Processor: K6
d. System Board P/N: 36L9051
Machine Type: 2153
Models: E2U, E2C, E3U
Processor: K6
e. System Board P/N: 00K8752
Machine Type: 2153
Models: E28, E29, E4A, E3T
Processor: Celeron
f. System Board P/N: 36L9049
Machine Type: 2153
Models: E1H, E3H, E1P, E3P
Processor: Celeron
[ NOTE 4: 2139 and 2153/K6 models are U.S. configurations
only; 2153/Celeron models are non-U.S. configurations - there
apparently are no U.S. configurations that use the Celeron
processor. Owners of all other 2139/2153 Aptiva models should
refer to the HMM to determine the appropriate system board
part number. ]
5. The switch settings discussed below (and PART II) in relation
to CPU upgrades should apply to all models that use the same
system board. However, my perspective is from the 2153E2N, so
if what I say regarding system boards other than 00K8747 is
incorrect or not applicable with regard to other models, feel free
to respond accordingly.
6. After installing a new CPU, you must verify and/or change
settings on one or more switchbanks that are mounted on the
system board before turning on the computer. Possible settings
can be found at the URLs listed above in NOTE 1 or in Chapter 5
of the HMM:
a. 2153/K6: Table 5-1, pages 5-4 and 5-5
(switchbanks SW1, SW2, and SW3)
b. 2153/Celeron: Table 5-4, page 5-9
(switchbank SW1)
c. 2139/PII: Table 5-6, page 5-13
(switchbank SW1)
7. APTIVA 2139 (SEE PART II FOR 2153/K6 AND 2153/CELERON
MODELS). The 2139 is the more advanced of the system
boards. It is designed to accommodate the Pentium II (PII)
processor. A single switchbank (SW1) with eight (8) switches
(located next to the center PCI expansion slot) is used to set
the bus frequency and processor speed. The individual switches
in switchbank SW1 are numbered SW1-1 through SW1-8. The
word "ON" should be stamped to one end of the switchbank.
The end switch nearest the word "ON" should be SW1-1. The
individual switches toggled towards the word "ON" are
considered 'ON', and those that are toggled away from the word
"ON" are considered to be 'OFF'.
a. The 2139 supports only two (2) bus frequencies: 66MHz and
100MHz. PII processors at speeds of 233 MHz, 266 MHz, 300
MHz, and 333 MHz must use a 66 MHz bus frequency. PII
processors at speeds of 350 MHz, 400 MHz, and 450 MHz must
use a 100 MHz bus frequency. The 2139/2153 HMM states that
the 2139 system board DOES support the 450 MHz PII
processor; therefore the 2139 should be able to be upgraded
without problem to the the fastest PII processor currently
available, the 450 MHz version.
b. The PII uses a Single Edge Contact Connector (S.E.C.C.)
form factor (formally known as "Slot 1"), which is a 242-contact
slot connector. The current "flavor" of the S.E.C.C. form factor
is S.E.C.C.2. Initial versions of the PII (and some Pentium IIIs)
use S.E.C.C. packaging; more recent versions use S.E.C.C.2.
The difference between the two S.E.C.C. versions concern
thermal-dissipation design and the retention mechanism used to
secure the processor to the 242-contact slot connector.
(1) The presence of an "extended thermal plate" will
differentiate between the two S.E.C.C. form factors: The
S.E.C.C. package has an extended thermal plate, and the
S.E.C.C.2 package does not. The extended thermal plate is a
metal skirt on the back side of the processor to which the
heatsink is attached. If the heat sink appears to be attached
directly to the processor "core" rather than to a metal plate
which is attached to the core, then it probably is a S.E.C.C.2
package.
(2) Another possible way to distinguish between the two
packages: you should see the words "Intel" and "Pentium II"
stamped on the top edge of the S.E.C.C. package, but not on
the S.E.C.C.2 package.
(3) Because of the different thermal designs of the two S.E.C.C.
packages, it is recommended that you buy an appropriate
thermal cooling solution (heatsink/fan assembly) at the same
time you purchase a new processor.
(4) The retention mechanism is NOT supplied with a new
processor - it is supplied by the system board manufacturer,
i.e., IBM. THIS MAY BE and issue when upgrading the CPU if
your original processor uses the S.E.C.C. package and you want
to install a different processor that uses the S.E.C.C.2 package.
The retention mechanisms for these two packages are different
and cannot be interchanged.
c. Switch settings. SW1-1 sets the bus frequency: 'ON' for 66
MHz and 'OFF' for 100 MHz. Since it is assumed that 2139 users
will be using processor speeds of 350 MHz or higher, SW1-1
should be set for 100 MHz, i.e., 'OFF'. SW1-2 doesn't deal with
the processor per se, so it should remain at it's default setting
of 'OFF'. SW1-3 and SW1-4 are "Reserved" and are not used -
leave them set at their current settings. SW1-5 through SW1-8
set the processor speed. Unlike the system board schematics
and HMM diagrams for the 2153/K6 and 2153/Celeron system
boards, the 2139 system board schematics and HMM diagrams
do not list specific switch settings for the different processor
speeds. Therefore, THE SWITCH SETTINGS LISTED BELOW ARE
MY BEST GUESS based on available documentation. If you have
one of the following processors and the switch settings are
different from what I say, please respond to this posting to let
others know. There are eight (8) possible "Slot 1 Core/Bus Clock
Ratio" options that can be set with SW1-5 through SW1-8. The
documentation lists the ratios as 2, 3, 4, 5, 5/2 (or 2.5), 7/2 (or
3.5), 9/2 (or 4.5), AND 11/2 (or 5.5). I surmise that these ratios
are the same as the Core Clock Multiplier parameter used with
the 2153/K6 system boards. Therefore, processor speed would
be the product of the bus frequency and the Slot 1 Core/Bus
Clock Ratio. Assuming use of a 100 MHz bus frequency and
Pentium II processor speeds greater than or equal to 350 MHz,
the following switch settings would be applicable:
(1) PII Processor: 350 MHz
Slot1 Core/Bus Clock Ratio: 7/2 (3.5)
SW1-5 / SW1-6 / SW1-7 / SW1-8
ON / OFF / OFF / ON
(2) PII Processor: 400 MHz
Slot1 Core/Bus Clock Ratio: 4
SW1-5 / SW1-6 / SW1-7 / SW1-8
OFF / ON / ON / ON
(3) PII Processor: 450 MHz
Slot1 Core/Bus Clock Ratio: 9/2 (4.5)
SW1-5 / SW1-6 / SW1-7 / SW1-8
OFF / ON / OFF / ON
d. Since the 2139 can already support the fastest PII
processor, the only upgrade question would deal with the
Pentium III (PIII) processor. The PII Xeon and PIII Xeon are not
options because they are a physically different processors and
will not fit in the 2139's 242-contact "Slot 1" connector. The
Xeon S.E.C.C. processors use a 330-contact "Slot 2" connector.
ABOUT THE ONLY WAY TO KNOW IF A PIII WILL WORK IS TO
TRY IT. The biggest question would be whether or not the
Aptiva 2139 BIOS supports the PIII. However, I doubt you will
get any substantial support from either IBM or the BIOS
manufacturer (assuming the BIOS manufacturer is ACER).
Therefore, you should update your BIOS through Update
Connector to insure you have the latest version possible. You
may also want to peruse the Intel web site
(http://www.intel.com) prior to upgrading. Below is a snapshot
of what I have found out:
(1) The PIII uses the same S.E.C.C./S.E.C.C.2 form factor as
the Pentium II; therefore a PIII will fit in the Slot 1 connector of
the 2139. However, make sure that the retention mechanism
that came with the 2139 will work with the PIII that you
purchase; otherwise you will need to obtain a compatible
retention mechanism. Any PIII currently purchased will most
likely use the S.E.C.C.2 form factor.
(2) You should purchase a new heat sink/fan unit with the PIII
because the faster speeds of the PIII will generate more heat,
and the cooling unit in the 2139 is probably only rated for the
maximum PII speed of 450 MHz. A good place to start
comparison shopping for a PIII is at
http://www.pricewatch.com./
(3) I could not find what the CPU core voltage is for the 2139,
and there does not appear to be any jumper or switch settings
on the motherboard for the CPU core voltage. However, both
the PII (350 MHz, 400 MHz, and 450 MHz) and the PIII are
designed to operate at a nominal core voltage of 2.0V; so core
voltage should not be an issue with the 2139. I have read that
the optimum core voltage for the PIII is 1.8V, but Intel lists
2.0V as being OK. If anyone knows more about the 2139 core
voltage setting and/or the PIII core voltage, please post it for
others to use.
(4) The PIII requires a 100 MHz bus frequency, which the 2139
supports; so bus frequency should also not be a problem. Just
insure SW1-1 is set to 'OFF'.
(5) PIII processors come in 450MHz, 500MHz, 550MHZ, and
600MHz. However, it appears that the 2139 system board only
supports up to 550 MHz (Slot 1 Core/Bus Clock Ratio of 11/2, or
5.5, with a 100 MHz bus). Therefore you should only purchase a
450MHz, 500MHz, or 550MHZ version of the PIII. Also, you
probably will not be able to overclock the PIII because Intel has
built in "frequency locking" and "clock locking" mechanisms to
prevent overclocking. The following system board switch
settings would be applicable (AGAIN, this is just my best
estimate from available documentation because I do not own a
2139. If anyone knows different from this, please speak up.):
(a) PIII Processor: 450 MHz
Slot1 Core/Bus Clock Ratio: 9/2 (4.5)
SW1-5 / SW1-6 / SW1-7 / SW1-8
OFF / ON / OFF / ON
(b) PIII Processor: 500 MHz
Slot1 Core/Bus Clock Ratio: 5
SW1-5 / SW1-6 / SW1-7 / SW1-8
OFF / OFF / ON / ON
(c) PIII Processor: 550 MHz
Slot1 Core/Bus Clock Ratio: 11/2 (5.5)
SW1-5 / SW1-6 / SW1-7 / SW1-8
OFF / OFF / OFF / ON
8. If anyone installs a PIII in their 2139, please post your
results. Also, if anyone has more to contribute about Aptiva CPU
upgrades in general, please do so, especially if anything said
here is incorrect. I will incorporate any other information for
future versions of this posting. Keeping this updated may help
others in the future as well as give the IBM support personnel a
break from being subject to the "kill the messenger" syndrome.
Topic: part two (5 of 9),
Conf: Aptiva 2139 and 2153
9. This is PART II of a two-part information posting regarding
Central Processing Unit (CPU) upgrades for the Aptiva 2153/K6,
2153/Celeron, and 2139 motherboards (hereafter referred to as
"system boards"). No IBM technical support is requested;
however, any experience/expertise/input that IBM would allow
their support personnel to contribute would be greatly
appreciated.
a. Paragraphs 2-6 of PART I contain general information about
upgrading the CPU in all of the Aptiva 2139/2153 models.
Paragraph 7 (in PART I) discusses CPU upgrades for the Aptiva
2139; and paragraphs 10 and 11 (IN PART II) pertain to the
2153/K6 and 2153/Celeron models, respectively. I recommend
reading paragraphs 2-6 in PART I before continuing with PART
II.
b. Information contained in both parts of this message is based
on my research as well as my experience in upgrading the CPU
in my 2153E2N. This message is a little lengthy in order to
accommodate anyone who may not be that proficient with
concepts and terminology, as well as to save some time for
those who may not be "research-inclined".
10. APTIVA 2153/K6 (SEE PART I FOR MODEL 2139). This
section is the most detailed considering my Aptiva uses the
2153/K6 system board, and the 2153/K6 system board has the
largest variety of CPU options that cover multiple manufacturers
(AMD, Intel, and Cyrix). The 2153/Celeron and 2139 system
boards were designed to accommodate only Intel processors.
a. Either myself or other forum participants have installed a
K6-2/366 (the fastest AMD processor available for a 66 MHz
bus), a K6-2/400 (the fastest AMD processor available for a 100
MHz bus), or a K6-2/350 (the fastest 100 MHz bus AMD
processor that is mentioned in the HMM). All of these
processors work as advertised. Although the switch settings
listed here are referenced to a 2153E2N system board, they
should be the same for all the other 2153/K6 models listed
above in paragraph 4.a, 4.b, and 4.c.
b. Looking at the 2153/K6 system board (with the chassis
standing normally and cover off), the three (3) applicable
switchbanks (SW1, SW2, and SW3) are located in the vicinity of
the CPU and the memory banks. SW2 is a set of eight (8)
switches to the right and near the "bottom" of the memory
modules. Also, SW2 is oriented "parallel" to the memory modules.
SW1 is a bank of four (4) switches and is located "above" SW2.
SW1 is set "perpendicular" to the memory modules. SW3 is
another set of four (4) switches that is located to the left of
the memory modules and directly above the CPU. SW3 is also
set "perpendicular" to the memory modules. The switchbanks
are silver with blue switches. One side of the switchbank should
have the word "ON" stamped on it. Switches toggled to the side
labeled "ON" are 'ON', and are 'OFF' when set to the opposite
side. The end switch to the left of the word "ON" is the #1
switch, with the remaining switches in the bank numbered
sequentially - for example, the switches in SW1 are referred to
as SW1-1, SW1-2, SW1-3, and SW1-4.
c. The three applicable switchbanks set the Bus Frequency,
Core Voltage, and Clock Multiplier for the CPU. In reality,
SW1-1, SW3-1, and SW3-2 do not specifically deal with the
K6-2 CPU, and should not be changed from their default
settings. SW1-2, SW1-3, SW1-4, SW3-3, and SW3-4 set the
bus frequency. SW2-1,-2,-3, and -4 set the clock multiplier;
and SW2-5,-6,-7, and -8 set the CPU core voltage.
d. My E2N came with a K6-2/266, which requires a 66 MHz bus
frequency, 2.2V core voltage, and 4.0X clock multiplier.
Referring to the HMM, the switch settings for this CPU are as
follows:
SW1: OFF-OFF-ON-OFF
SW2: ON-OFF-ON-OFF-OFF-OFF-ON-OFF
SW3: ON-ON-OFF-OFF
e. UPGRADING TO K6-2/366. I have installed a K6-2/366 CPU,
which also requires a 66 MHz bus and 2.2V core voltage, but
uses a 5.5X clock multiplier. The switch settings are as follows:
SW1: OFF-OFF-ON-OFF
SW2: OFF-OFF-ON-OFF-OFF-OFF-ON-OFF
SW3: ON-ON-OFF-OFF
When analyzing these switch settings, you can see that the
ONLY switch requiring a different setting when upgrading from a
K6-2/266 to a K6-2/366 is SW2-1. SW2-1 must be toggled from
"ON" to "OFF", which changes the clock multiplier from 4.0X to
5.5X - all other switch settings are the same for both CPUs.
[ NOTE 5: The following anomaly MAY or MAY NOT occur with
the K6-2/366 (and K6-2/400) processors; so this discussion is
included 'just in case' ]: Upon starting the computer for the first
time after installing the new CPU, the Power-On Self-Test
(POST) will pause, and the screen will list two error messages:
0127. CPU Clock Mismatch
0162. Equipment Configuration Error
At the bottom of the screen will be the following:
Press 'F1' to enter Setup or 'Enter' to continue...
These error messages are harmless. Just press 'Enter' and the
computer will continue to boot normally. All subsequent boots
will also be normal - the BIOS automatically updates the CPU
information. If you press 'F1', or if you enter Setup at any later
date, then you will find only one different piece of information -
"Processor Speed" under the "System Information" menu will
have changed from "266 MHz" to "333 MHz", which is probably
the reason for the error messages. Although this information
block does not say "366 MHz" or "400 MHz", there is nothing
wrong with the CPU. I ran three different software tests that
measure CPU speed, and all three registered speeds at or near
366 MHz/400 MHz. I do not know for sure why the BIOS will not
recognize the correct CPU speed, but it does not affect system
operation.
f. UPGRADING TO K6-2/350. One other forum participant has
posted that he had no problem installing an AMD K6-2/350
processor in the 2153E2N. There were no reported error
messages or BIOS discrepancies when upgrading to this
processor. The K6-2/350 requires a bus frequency of 100 MHz,
a core voltage of 2.2V, and a clock multiplier of 3.5X. Therefore,
to upgrade from the standard K6-2/266 in the E2N model, you
would have to change switch settings for both the bus
frequency and the clock multiplier. The switch settings for the
K6-2/350 are be as follows:
SW1: OFF-ON-OFF-OFF
SW2: OFF-OFF-OFF-OFF-OFF-OFF-ON-OFF
SW3: ON-ON-ON-ON
g. UPGRADING TO K6-2/400. Both one other forum participant
and myself have satisfactorily upgraded to an AMD K6-2/400
CPU. The K6-2/400 requires a bus frequency of 100 MHz, core
voltage of 2.2V, and a clock multiplier of 4.0X. The switch
settings for the K6-2/400 are as follows:
SW1: OFF-ON-OFF-OFF
SW2: ON-OFF-ON-OFF-OFF-OFF-ON-OFF
SW3: ON-ON-ON-ON
h. The 2153/K6 is also capable of setting the bus frequency to
95MHz. The fastest AMD processor available for the 95 MHz bus
setting is the K6-2/380. This processor also has a 2.2V core
voltage, and uses a 4.0X clock multiplier. The switch settings
for the K6-2/380 are as follows:
SW1: OFF-OFF-OFF-OFF
SW2: ON-OFF-ON-OFF-OFF-OFF-ON-OFF
SW3: ON-ON-ON-OFF
[ NOTE 6: When reviewing the motherboard schematics for the
2153 (they're a little cryptic), it looks as if the 95 MHz bus
setting is not supported by the E2N and E3N, only the E4N, E2U,
E2C, and E3U. It appears the E2N and E3N support a 75 MHz
bus frequency in lieu of the 95 MHz setting (and vice versa).
Therefore, I recommend NOT considering a 95 MHz bus CPU
(i.e., the AMD K6-2/380) for the E2N or E3N, but it should be OK
for the E4N, E2U, E2C, and E3U. ]
i. A few more notes on processors for the 2153/K6
(1) I paid $85.00 for the AMD K6-2/366 and $89.00 for the AMD
K6-2/400. Both purchases included a new heat sink/cooling fan
unit. However, I have noted that online prices vary widely. You
should be able to get any of the faster processors and an
upgraded cooling assembly for less than $100.
(2) The K6-2/400 (at least) will require a new heat sink/fan unit
to provide appropriate cooling for the faster CPU. When I
bought the K6-2/366 I also bought a new cooling unit just to be
safe (only $9.00). The HMM indicates that the heat sink/fan
unit that came with the 2153 would work with CPUs up to, and
including, the K6-2/350; anything higher is in question. With
such a low cooling unit cost, it would be best to stay
conservative and purchase a cooling unit designed for whatever
processor you want to install.
(3) AMD does make faster processors than what I listed above;
however, they will not work in a 2153/K6. The K6-2/450,
K6-2/475, K6-3/400, and K6-3/450 use a core voltage of 2.4V,
which the 2153 motherboard does not support.
(4) The 2153 motherboard is a Socket 7 design, and therefore
requires dual-voltage CPUs: a core voltage within the CPU, and
an I/O voltage for circuitry outside the CPU. Multiple core
voltages are supported on the motherboard; however, there is
only one I/O voltage - 3.3V. Therefore, ANY new CPU you
purchase must be dual-voltage, and the I/O voltage must be
3.3V. The core voltage can be any that the motherboard
supports: 2.2V, 2.3V, 2.8V, 2.9V, 3.2V, and 3.3V).
(5) Intel (P55C) CPUs. Commonly referred to as the Pentium
Processor with MMX Technology, the P55C is the ONLY Intel
CPU that will work on the 2153/K6. Such Intel processors as
Pentium II, Pentium III, Pentium II/III Xeon, or OverDrive
processors are not applicable and should not be considered. The
P55C is intended to be used with a 66 MHz bus, a 2.8V core
voltage, and clock multipliers of 2.5X, 3.0X, and 3.5X. Since
CPU speed is the product of the frequency bus and the clock
multiplier, the maximum possible CPU with the P55C is nominally
233 MHz (66 MHz X 3.5). You could "overclock" the system by
using a 100 MHz bus speed and IF it worked (I don't really know
if you even can do this) the CPU speed should be around 350
MHz. However, these speeds can be matched or beat by AMD
processors; so upgrading with an Intel processor seems to be a
dead-end, and is therefore not recommended.
(6) Cyrix (M2) CPUs. As with the P55C, the Aptiva system board
only supports clock multiplier settings of 2.5X, 3.0X, and 3.5X
for the Cyrix MII line of processors. Cyrix MII processors come in
speeds of 300 MHz, 333 MHz, 366 MHz, 400 MHz, and 433 MHz.
Considering the maximum speed that can be set for a Cyrix CPU
is 350 MHz (3.5X clock multiple and 100 MHz bus), you would
have to purchase either the 333 MHz MII (and therefore
"overclock" the CPU), or the 400 MHZ version (and therefore not
get your money's worth by not realizing the full potential of the
CPU). Like the Intel P55C, these speeds can also be matched or
beat by AMD processors; so it is best to go with AMD for the
maximum upgrade to CPU speed. However, if a Cyrix MII CPU is
desired, then it is recommended to go with the 400 MHz version
in order to avoid the possible negative consequences associated
with overclocking (see the next paragraph). Overclocking the
333 MHz CPU will also void the computer's warranty.
(7) There does exist a practice known as "overclocking"
whereby you set the bus and/or clock multiple to realize a
higher speed than manufacturer specifications. For instance,
the K6-2/350 uses a 100 MHz bus and a 3.5X clock multiplier. If
you set the clock multiplier to 4.0X or 4.5X, you should realize a
faster processor speed. However, I do not recommend doing it.
Besides voiding the computer's warranty, the increased thermal
stress to the CPU, RAM, and supporting chips (assuming the
computer boots OK) will cause a gradual degradation to these
parts. You also may experience system hangs and crashes,
together with a loss of any application data that hasn't been
saved. Key ingredients for minimizing the adverse effects of
overclocking are the quality of the motherboard, type of RAM,
and, most of all, cooling. If you decide to overclock your CPU,
you should get a higher capacity heatsink/fan before resetting
the clock multiplier. Also, you may want to start small and work
your way up the speed settings while keeping an eye on
performance. Use a benchmark testing program from sources
such as Ziff Davis (http://www.zd.com) or Windows Magazine
(http://www.winmag.com) to test the CPU for reliable
performance at increased speeds. Good discussions of, and
guidance for, overclocking CPUs can be found at
http://www.anandtech.com/html/print_review.cfm?document=157
and
http://www.conceptmfg.com/clockquest.html.
11. 2153/CELERON. CPU-wise, it looks to be the simplest
configuration of all. The system board is designed to handle only
four (4) different Celeron processor speeds: 233 MHz, 266 MHz,
300 MHz, and 333 MHz. A single switchbank (SW1) with eight
(8) switches (located next to the inboard ISA expansion slot) is
used to set the processor being used. See paragraph 7.a above
for interpreting switch numbering. SW1-1 and SW1-2 are not
actually required for setting the Celeron processor speed, so
they should remain at their default settings, i.e., SW1-1=OFF
and SW1-2=ON. SW1-3 through SW1-6 are set as follows for
each applicable processor:
Celeron Processor / SW1-3 / SW1-4 / SW1-5 / SW1-6
233 MHz / ON / OFF / OFF / ON
266 MHz / OFF / ON / ON / ON
300 MHz / OFF / ON / OFF / ON
333 MHz / OFF / OFF / ON / ON
The Celeron Processor is designed to operate ONLY with a 66
MHz bus; therefore these switches are most likely setting the
clock multiplier (3.5X, 4.0X, 4.5X, and 5.0X respectively). Even
though Intel is marketing faster Celeron processors (366 MHz,
400 MHz, 433MHz, and 466 MHz), the only possible processors
that can be used on the 2153/Celeron system board are those
listed above because there are no switch settings to
accommodate faster processors. Additionally, Intel is NOT going
to offer OverDrive processors for Celeron-processor based
systems; so what you see above is all you can do as far as the
CPU is concerned.
pstach wrote:
>
>
> are there any switch settings on the motherboard that have to be
> changed to install a new cpu in a 2139
--
Posted via CNET Help.com
http://www.help.com/
Chuck2
to the following board and do a search on 2139 Upgrades. Lots of people
have upgraded and the pertinent information is already there.
http://novogate.efront.com/cgi-bin/aptiva/Ultimate.cgi
LOL Oh yes, I upgraded my 2153E2N from 266 to 550mhz.
pstach wrote:
>
>
> are there any switch settings on the motherboard that have to be
> changed to install a new cpu in a 2139