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Member Since 19 Apr 2008
Offline Last Active Feb 02 2014 01:51 AM

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In Topic: CUDA-Z Info+Bench (Nvidia only) - updated Dec 2015

20 July 2011 - 06:16 AM

Lion is soon out and folks will be able to benchmark GTX 5xx series.

The following is taken from my Windows 7 box running a pair of GTX 560's. They came factory OC'd at 900/1800/2004 (4008) 1.012 volts. However, I under-clocked/under-volted them down to 855/1710/2100 (4200) 0.987 volts.

Single-Precision: ./nbody -n=61440 -benchmark

-- One GPU: 548.804 single-precision GFLOP/s
-- Two GPUs via -numdevices=2: 1068.541 single-precision GFLOP/s

Double-Precision: ./nbody -fp64 -n=30720 -benchmark

-- One GPU: 89.702 double-precision GFLOP/s
-- Two GPUs via -numdevices=2: 166.125 double-precision GFLOP/s

I wish that NVIDIA will one day make a single-PCB card containing 2 GTX 560's to have a good balance for compute-power and electric power utilization.

In Topic: CUDA-Z Info+Bench (Nvidia only) - updated Dec 2015

20 July 2011 - 04:58 AM

One can even benchmark double-precision via the N-Body CUDA demo. GTX 4xx owners will be able to see a much larger increase in performance when comparing to GTX 2xx cards.

Here are my results:

./nbody -fp64 -n=30720 -benchmark

GTX 295 OC'ed:

-- One GPU: 66.966 double-precision GFLOP/s
-- Two GPUs via -numdevices=2: 128.672 double-precision GFLOP/s

GTX 295 (standard clocks):

-- One GPU: 55.010 double-precision GFLOP/s
-- Two GPUs via -numdevices=2: 106.478 double-precision GFLOP/s

This is where a GTX 4xx can shine over a GTX 2xx variant.

Try -n=15360 if -n=30720 reports unspecified launch failure.
Not all cards support double-precision.

In Topic: Nvidia GTX 295 Black Screen

20 July 2011 - 04:28 AM

Steps to go from 10.6.7 to 10.6.8: (for folks already with a working 10.6.7 or earlier and a GTX 2xx card)

1. Ensure your gfx.plist has device_type set correctly. Read my previous post here in the forum.
2. Create the hex via gfxutil and update the EFI string in your boot plist file.
3. Reboot to ensure your 10.6.7 is working
4. Then, follow Tommy's OS update via #####
5. The 10.6.8 OS should boot up fine with the graphics card using the update boot plist

Afterwards, you can then set GraphicsEnabler to No and test or just leave it if all is fine.
GTX 295 folks will need to set that to No and update to Nvidia's driver for CUDA to work.

In Topic: Nvidia GTX 295 Black Screen

20 July 2011 - 03:51 AM

My GraphicsEnabler is set to No in my boot.plist file.

Here's a suggestion for folks who currently have a working 10.6.7 and a GTX 2xx card.

1. Look at the device_type entry
2. 10.6.8 requires that to be set to NVDA,Parent versus NVDA,GeForce

Previously, we had this with 10.6.7 and below.


In 10.6.8, it needs to be the following: (name is not necessary).
This works with both 10.6.7 and 10.6.8


So, just make that change to your current EFI plist file and update the EFI string in your boot plist file prior to updating to 10.6.8.

Folks running a GTX 295 card (single-PCB edition) will need Nvidia's Quadro 4000 drivers in order for CUDA to work. The reason is that Apple's native Nvidia driver is not able to properly configure one of the GPUs. However, the system will load and OpenGL is fine.

I hope this helps folks out there who are currently running a GTX 2xx card successfully with 10.6.7 or earlier and wanting to update to 10.6.8.

Tip for the GTX 295 single-PCB edition:

A GTX 295 single-PCB edition requires the device-type entry to be set to NVDA,GeForce for the first GPU (0x0,0x0) and NVDA,Parent for the 2nd GPU (0x2,0x0).

A GTX 295 dual-PCB edition (I believe) may need device_type for both GPUs to be set to NVDA,Parent. (I'm not sure... someone with a dual-PCB can verify...)

- meroy

In Topic: CUDA-Z Info+Bench (Nvidia only) - updated Dec 2015

19 July 2011 - 08:38 PM

Hi all,

Just wanted to chime in to say that I finally got sleep working on my system with the GTX 295 card.


Note: The culprit was was with the device-type. Each GPU is different. The one having display connections is set to NVDA,Parent and the other to NVDA,GeForce.
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