GPU Credit adjustment

[dyeman]

GPUGrid have determined that they are underclaiming credits, and will adjust in future version of the client.  Also, they have decided to award a 50% bonus for results returned within 24 hours (see thread).  This is touch and go on my 9800GT which has been taking over 12 hours for a WU and GPUGRID fetches 2 WUs, but luckily I got a short WU (10 hours) and got a 50% bonus on the last WU returned.  They may increase the bonus time limit from 24 to 36 hours which would be great.  In the meantime a bit of babysitting.

No doubt this decision will provoke some lively discussion!

[Tixx]

wow, that is alot of credit!! NOICE:)

[veebee]

I still dont get exactly how these GPU work units are actually "crunched"..

I heard someone hereon our forum say that the time shown in Boinc-manager is only the amount of time that a CPU spends on the WU....

Why then doesn't suspending all other work except GPU result in the WU just ticking over like a normal WU from anyone else ?

I ask this as Dyeman's post seems to say that all "batches" (ie his 2 that GPU grid fetches at a time) must be returned in that time. I think mine grabs two at a time as well, but it does it even when I have it set to "no new work", and basically does it anytime I "update" GPU grid on the BM.

Any plain English explanation would be appreciated.

Thanx

[Wang Solutions]

GPU WUs are crunched by the GPU rather than the CPU, though they do use a small amount of CPU time to "feed" the work to the GPU. It tends to be this CPU time that shows in the BOINC Manager, so it in no way reflects the actual time that the work takes. Because the GPUs have many cores they can crunch a lot more work than the CPU can in any given time period, hence the credit for GPU work appears much higher than for CPU work. The GPU tends to run at capacity, so disabling other work through the CPU will not influence the crunching time for GPU work.

The BOINC Manager seems to be programmed to download GPU work according to how many CPU cores a computer has. This is not particularly logical but is the current system though I expect that this will change as the system evolves and newer BOINC versions are released. What it means currently is if you have the card in a single core or dual core machine, you are more likely to be able to return the work within the "bonus" period than you are on a quad core or i7, unless you micromanage it closely. My computers do NOT download GPU work when I have it set to NNW, and would be surprised if yours does. It should not happen, so if it does it is probably a bug in your BOINC version - I still use 6.4.5 and it works correctly.

[yoda]

Yes, it's prtobably a bug.

However, setting a small cache helps too.  I am running GPUGrid on a Q6600 with 9800GT card and usually only have two GPUGrid WU in the system.  That's with a cache of about 0.1 days

[dyeman]

For me. GPUGRID seems always to try to keep 2 WUs in the cache - when one is uploaded a replacement is downloaded.  Thhis is with a 2 day cache (Settings: Computer is connected to the Internet about every 0 days, Maintain enough work for an additional 2 days).  So if the card takes 12 hours and 1 minute to process a WU, the elapsed time for each WU would be 24 hours and 2 minutes and miss out on the bonus.  At 11 hours and 59 minutes it would be OK.  If they increase the limit for the bonus to 1.5 days the there should be no problem.

In the interim, setting NNT until a Wu is well progressed before manually downloading the second WU should ensure getting the bonus credit (I hate babysitting.. :-\)

[yoda]

Done lots of overtime this week so I might look at getting a GTX260 soon ;D

[dyeman]

A GTX260 will have no problem meeting the 24 hour deadline !! ;D

[veebee]

what about the 250 ?? that's about my spend limit ATM...

[Furlozza]

I'll let ya know when the AA finishes. Will try the GTS 250 in TheGnat first, and then iGnatious

[dyeman]

GTS 250 is essentially the same as a 9800 GTX+. It has a few more shaders than 9800 GT and they are significantly faster, so I reckon it should have no problem meeting the 12 hour elapsed time required to beat the 24 hour deadline (and certainly no issue if the deadline is increased to 36 hours)

[Furlozza]

Don't ya just love it when the latest file downloaded from GPRGrid says that it has a completion time of 48 hrs?? Not even a 280 could process that within 24 hrs *GRRRRRRRRRRRRRRRRRRRRRRRRRRRRR*

[dyeman]

To easy the effort, we are giving now:
60%+ for WUs returned within 1.5 days
20%+ for Wus returned within 2.0 days

We will probably also extend the deadline to 5 days for all the others.

gdf

Update on the deadline thresholds.

[Wang Solutions]

Don't ya just love it when the latest file downloaded from GPRGrid says that it has a completion time of 48 hrs?? Not even a 280 could process that within 24 hrs *GRRRRRRRRRRRRRRRRRRRRRRRRRRRRR*

Hey, I have been getting some with an estimated completion time of 110 hours! Go figure how you return that within the deadline of 4 days! Mind, you I did manage to process one of these in 110 hours, and even though it was half a day beyond deadline it still got credit.  biggrin

[Furlozza]

WS

I trust the reward was worth the effort? That is, more than 4000 credits per WU