Why does Blas play better than OpenCL?

[Brian McKeever]

I've tried many different networks, and Blas always outperforms OpenCl with the same network on my computer.
Here's the results of a 5 round, round robin 20/30 tournament played on arena with default settings:
Engine Score Bf Of B8 O8 S-B
1: Bf Lc0_blas f926cbad 10.5/15 ····· 11==0 ===1= 11=11 65.25
2: Of Lc0 Open CL f926cbad 8.0/15 00==1 ····· 00=1= 11==1 53.00
3: B8 Lc0_blas 8e36e7bb 7.0/15 ===0= 11=0= ····· ===0= 54.00
4: O8 Lc0 OpenCL 8e36e7bb 4.5/15 00=00 00==0 ===1= ····· 34.25

I've benchmarked everything.
Blas 8e36e7bb2f857eadf3163cb5d6cc3c5800fac0eba5951f8b1e51e3b732ee938b gets 3.43924 nodes per second.
Blas f926cbadc7aebbd032a6ad7d8ecf2ac3dd5324f9e3c036f96de9375931a55a0f gets 2.80217 nodes per second.
OpenCL 8e36e7b... gets 214.776 nodes per second.
OpenCL f926cba... gets 206.666 nodes per second.

Why doesn't 2 orders of magnitude more nodes per second lead to better results?

My comp is old. This is what it says I have:
Platform version: OpenCL 2.0 AMD-APP (1800.11)
Platform profile: FULL_PROFILE
Platform name: AMD Accelerated Parallel Processing
Platform vendor: Advanced Micro Devices, Inc.
Device ID: 0
Device name: Barts
Device type: GPU
Device vendor: Advanced Micro Devices, Inc.
Device driver: 1800.11 (VM)
Device speed: 775 MHZ
Device cores: 12 CU
Device score: 1120
Device ID: 1
Device name: AMD A6-3650 APU with Radeon(tm) HD Graphics
Device type: CPU
Device vendor: AuthenticAMD
Device driver: 1800.11 (sse2)
Device speed: 2600 MHZ
Device cores: 4 CU
Device score: 1020
Selected platform: AMD Accelerated Parallel Processing
Selected device: Barts
with OpenCL 2.0 capability.
Loaded existing SGEMM tuning for batch size 16.
Wavefront/Warp size: 64

[Brian McKeever]

I was expecting you guys to tell me I'm doing it wrong or I misunderstood something. Does that mean this is a bug I should report? Is blas stronger than opencl on your machines?

[Hoang Hiep Vu]

I never test blas or opencl so I can not say much. But could you retest by using cutechess-cli and run about 100 games (with short time control to be fast) head to head between 1 net of opencl and blas? 

Arena is notorious for many problems, and should not to be trusted (it can use an old engine while you believe it is a new one).

[MindMeNot]

I have myself experienced your problem on a new intel processor and its integrated graphics, blas was substantially better than opencl at same nodes per move. To know for sure, please run a 100 games head-to-head match.

[Brian McKeever]

I couldn't get cutechess-cli to work, so I tested with Lucas chess. The results are blas has 49 wins, 43 draws, and 8 losses.

The network used for both was 8e36e7bb2f857eadf3163cb5d6cc3c5800fac0eba5951f8b1e51e3b732ee938b which had the highest rating in the network spreadsheet a week or so ago.

The settings were no opening book, the regular initial position, 5 minutes base time with a 20 second increment, and default settings for leela.

Is that evidence good enough?

[colski]

You're right that all things being equal, more nps should be stronger. Perhaps your drivers haven't been updated? Old drivers could contain bugs.

https://www.amd.com/en/support/apu/amd-series-processors/amd-a6-series-apu-for-desktops/a6-3650-radeon-hd-6530d

Your gpu might be otherwise faulty, for example overheating.

[Walid Doknichot]

hi brian..........you as me ....blas not stranger than open cl......but some times yes....wen cpu stranger than gpu........go to bench of gpu .....i give you exempel......i5 3.4ghz whithe  blas is strang than amd hd 5450.....in general open cl be stranger than cpu if the giflops up than 80...or 100....less than 100 giflops...the cpu be  better than open cl.

[Brian McKeever]

I tried updating my graphics card driver, but it says I have the latest version.
It has a temperature gauge. It idles at 50 degrees c with a 48% fan speed. When I run two open cl bots against each other, it goes to 74 degrees c with a 73% fan speed. My research says 95 degrees c is when it'd be overheating. Also, I don't remember when I bought this computer, but it was 5+ years ago. It's never done anything to make me suspect it's faulty.

[Brian McKeever]

I don't know how to benchmark like you want, but I benchmarked opencl vs blas with leela. Blas was getting 2-3 nodes per second. OpenCL was getting 200+.