Why the calculation time is very different?

AgentB
AgentB
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PCIe x8 may be a factor and i

PCIe x8 may be a factor and i noticed a "?" next to it  on the screenshot - someone who knows win things and techpowerup may have some ideas. 

I noticed the OpenCL tickbox was also clear.

 

 

Richie
Richie
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freestman, could you update

freestman, could you update GPU-Z to new version please. There's been many fixes. Let's see if 2.5.0 will show identical information.

https://www.techpowerup.com/download/techpowerup-gpu-z/

That "?" next to Bus interface information is just a box leading to an inbuilt Render test.

freestman
freestman
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The other same model card is

20180109_101400_1.jpg

The other same model card is on different machines

https://einsteinathome.org/host/12440971/tasks/0/0

20180109_103714_1.jpg

6xxx seconds per task

sig-1531.png

Gary Roberts
Gary Roberts
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AgentB wrote:PCIe x8 may be a

AgentB wrote:
PCIe x8 may be a factor ...

These days, I have a number of dual GPU setups, both RX 460 and R7 370.  I take care to 'match' the GPUs - same brand, same model.  The motherboards have x16 slots that are x16, x4 electrically.  The first thing I noticed was that the device that BOINC identified as device 1 was a bit faster than device 0.  I assumed that device 0 would be in the x16 slot and device 1 would be x4 -- obviously not, so it would seem.

The difference wasn't all that large, particularly with Polaris, so I didn't investigate further.  The worst case I recall seeing was with dual R7 370s with both devices running GPU tasks 2x (4 GPU tasks all up).  Device 0 was reporting crunch times of around 37 mins and device 1 around 33 mins.

Presumably PCIe x8 should be less of an issue than PCIe x4 and might contribute to a slowdown but perhaps not the variability of any slowdown.

 

Cheers,
Gary.

freestman
freestman
Joined: 16 Jun 08
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Credit: 1,973,007,618
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The same card is on different

20180109_102631_1.jpg

The same card is on different machines

https://einsteinathome.org/host/12254525/tasks/0/0

20180109_103923_1.jpg

6xxx seconds per task

sig-1531.png

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