Hello all,
I was running a protein lipid system of 133,835 atom in GPU K40 using
pmemd.cuda.MPI. The speed I am getting is considerably low. I checked with
benchmark given in GPU Support, Amber website and found some issues with
the performance. Here are the speed I am getting (in ns/day):
Factor IX (90,906 atoms), NPT
-----------------------------
Given speed in K40 cards: 68.38 (4 x K40), 51.90 (2 x K40)
Speed I am getting : 33.96 (4 x K40, with 4 processors), 47.53 (2 x
K40 with 2 processors)
Cellulose (408,609 atoms): NPT
------------------------------
Given speed in K40 cards: 17.34 (4 x K40), 12.33 (2 x K40)
Speed I am getting : 7.86 (4 x K40, with 4 processors), 8.66 (2 x K40
with 2 processors)
ECC was turned off in each 4 cards and boost clocks were turned on as per
'Considerations for maximizing GPU Performance' given in the website.
The issue is - 4 cards are not giving increased speed than 2 cards! While
running my system of 133,835 atom in 4 cards and 2 cards, I am getting the
following information with nvidia-smi command:
------------------+
| NVIDIA-SMI 352.39 Driver Version: 352.39
|
|-------------------------------+----------------------+----------------------+
| GPU Name Persistence-M| Bus-Id Disp.A | Volatile Uncorr.
ECC |
| Fan Temp Perf Pwr:Usage/Cap| Memory-Usage | GPU-Util Compute
M. |
|===============================+======================+======================|
| 0 Tesla K40c Off | 0000:02:00.0 Off |
Off |
| 25% 52C P0 94W / 235W | 607MiB / 12287MiB | 56%
Default |
+-------------------------------+----------------------+----------------------+
| 1 Tesla K40c Off | 0000:03:00.0 Off |
Off |
| 26% 54C P0 91W / 235W | 678MiB / 12287MiB | 35%
Default |
+-------------------------------+----------------------+----------------------+
| 2 Tesla K40c Off | 0000:83:00.0 Off |
Off |
| 24% 49C P0 88W / 235W | 678MiB / 12287MiB | 31%
Default |
+-------------------------------+----------------------+----------------------+
| 3 Tesla K40c Off | 0000:84:00.0 Off |
Off |
| 25% 50C P0 90W / 235W | 679MiB / 12287MiB | 35%
Default |
+-------------------------------+----------------------+----------------------+
+-----------------------------------------------------------------------------+
| Processes: GPU
Memory |
| GPU PID Type Process name
Usage |
|=============================================================================|
| 0 21674 C ...midhun/AMBER16/amber16/bin/pmemd.cuda.MPI
507MiB |
| 0 21675 C ...midhun/AMBER16/amber16/bin/pmemd.cuda.MPI
73MiB |
| 1 21674 C ...midhun/AMBER16/amber16/bin/pmemd.cuda.MPI
73MiB |
| 1 21675 C ...midhun/AMBER16/amber16/bin/pmemd.cuda.MPI
578MiB |
| 2 21676 C ...midhun/AMBER16/amber16/bin/pmemd.cuda.MPI
578MiB |
| 2 21677 C ...midhun/AMBER16/amber16/bin/pmemd.cuda.MPI
73MiB |
| 3 21676 C ...midhun/AMBER16/amber16/bin/pmemd.cuda.MPI
73MiB |
| 3 21677 C ...midhun/AMBER16/amber16/bin/pmemd.cuda.MPI
578MiB |
+-----------------------------------------------------------------------------+
[midhun.localhost Sys3-25]$ nvidia-smi
Fri Jul 13 15:33:25 2018
+------------------------------------------------------+
| NVIDIA-SMI 352.39 Driver Version: 352.39
|
|-------------------------------+----------------------+----------------------+
| GPU Name Persistence-M| Bus-Id Disp.A | Volatile Uncorr.
ECC |
| Fan Temp Perf Pwr:Usage/Cap| Memory-Usage | GPU-Util Compute
M. |
|===============================+======================+======================|
| 0 Tesla K40c Off | 0000:02:00.0 Off |
Off |
| 25% 51C P0 63W / 235W | 23MiB / 12287MiB | 0%
Default |
+-------------------------------+----------------------+----------------------+
| 1 Tesla K40c Off | 0000:03:00.0 Off |
Off |
| 26% 53C P0 63W / 235W | 23MiB / 12287MiB | 0%
Default |
+-------------------------------+----------------------+----------------------+
| 2 Tesla K40c Off | 0000:83:00.0 Off |
Off |
| 32% 71C P0 145W / 235W | 677MiB / 12287MiB | 88%
Default |
+-------------------------------+----------------------+----------------------+
| 3 Tesla K40c Off | 0000:84:00.0 Off |
Off |
| 32% 71C P0 144W / 235W | 763MiB / 12287MiB | 99%
Default |
+-------------------------------+----------------------+----------------------+
+-----------------------------------------------------------------------------+
| Processes: GPU
Memory |
| GPU PID Type Process name
Usage |
|=============================================================================|
| 2 21795 C ...midhun/AMBER16/amber16/bin/pmemd.cuda.MPI
576MiB |
| 2 21796 C ...midhun/AMBER16/amber16/bin/pmemd.cuda.MPI
73MiB |
| 3 21795 C ...midhun/AMBER16/amber16/bin/pmemd.cuda.MPI
73MiB |
| 3 21796 C ...midhun/AMBER16/amber16/bin/pmemd.cuda.MPI
663MiB |
+-----------------------------------------------------------------------------+
Why the GPU usage is like 56%,35%,31% and 35% while running in 4 GPU cards
while running in 2 cards gives 88% and 99%?
I was getting 27.11 ns/day in 2xK40 and 21.09 ns/day in 4xK40 cards. Why am
I not getting an increased speed? Please reply.
--
*MIDHUN K MADHU*
Ph.D Student
Dept. of Biological Sciences
IISER Bhopal
--------------------------------
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Received on Fri Jul 13 2018 - 04:00:01 PDT
