I try to answer some of the doubts that I see in the forum.

ATI and Nvidia have been head-to-head for a long time with pro and cons on each vendor.

Firestream ATI or other top ATI cards have more or less the same flops of top Nvidia cards in single precision.

http://en.wikipedia.org/wiki/GeForce_200_Series
http://en.wikipedia.org/wiki/Comparison_of_ATI_Graphics_Processing_Units

Nvidia seems so far better in GPGPU programming with CUDA and GPGPU hardware support. For a complex code, this is the best solution until OpenCL comes out and ATI adapts their hardware.

ATI is so far better in double precision performance, but this is still much less than single-precision performance anyway.



gdf

Nvidia seems so far better in GPGPU programming with CUDA and GPGPU hardware support. For a complex code, this is the best solution until OpenCL comes out and ATI adapts their hardware.

ATI is so far better in double precision performance, but this is still much less that single-precision performance anyway.

That is right. CUDA is currently the much more matured SDK than Stream is. Implementing a complex algorithm with CUDA should be much more straightforward than on ATI hardware in the moment, which makes the life easier for the developer. Furthermore, some of the hardware functionality needed to speed up some algorithms is only implemented in ATI's HD4000 series (with support in high level languages like Brook only slowly arriving), whereas on the nvidia side such features are already available in earlier cards.
We will have to wait another 3 months or so before one can start to compare the OpenCL implementations of both manufacturers.

Concerning the single/double precision performance of ATI and nvidia you are also right. With single precision nvidia and ATI are roughly on par (ATI claims only slightly higher theoretical values). But when going to doubles the nvidia performance reduces to about 8% of the single precision throughput, while ATI is able to sustain 20% of its advertized single precision peak performance. That means a HD3850 has about the same theoretical double precision performance as a GTX285 and a HD4800 series card is significantly faster for such things.

Hi,
ACEMD uses only single-precision on the gpu for maximum performance.
As you say the double precision performance of ATI is still 5 times less than any ATI or NVIDIA GPUs in single precision.

Fortunately, for molecular dynamics applications is ok to use single-precision.

gdf

Hi,
ACEMD uses only single-precision on the gpu for maximum performance.
As you say the double precision performance of ATI is still 5 times less than any ATI or NVIDIA GPUs in single precision.

Fortunately, for molecular dynamics applications is ok to use single-precision.

I know. I only wanted to quantify that "much less than single-precision performance".

By the way, could you have a look in the credit calculation thread?

> By the way, could you have a look in the credit calculation thread?

DONE.

Theory is beautiful but life is brutal:

In GPUGRID with 3xGTX260SP216 you may have 55000 credits per day,

In MilkyWay with 2xHD4870 you may have 110 000 credits per day...

So where is balance?

In MilkyWay project you may run 2 wu per gpu.
In gpu grid you may run only 1 wu per gpu.

So I really like GPUGRID, and this is only reason why I recently, when I was upgrading my computers I buy 3GTX260 not 3 HD4870.....

After all, I am not happy when I see so big differences in the scoring.

---

POLISH NATIONAL TEAM - Join! Crunch! Win!

Hi,
thanks for your preference.
The 260 are not the fastest card, but I understand what you mean.

gdf

Another horrifying statistics:

In MilkyWay...

This host

may crunch almost 400 000 Credits per day!!!

2xHD4870x2....

In GPUGRID fastest computer - 3xGTX295 make.... only..... almost 100 000 per day :(

NO COMMENT....

---

POLISH NATIONAL TEAM - Join! Crunch! Win!

I have a favour for administrators. Standardize the scoring so that there are no such irrational differences....

Is the MilkyWay@Home project apart from principles to which they are applying Seti@Home and GPUGRID?

---

POLISH NATIONAL TEAM - Join! Crunch! Win!

Milkyway released their source code and people wrote optimized apps. Some of the improvements made their way into the standard client, but the last batch (about a half year old) of optimizations didn't. The optimized clients for cpus are about a factor of 4 faster than the stock client. For the stock client the credits are OK, but optimized ones get proportionally more.

My 4870 has almost reached 80k RAC there. If you divided this by 4 the number would be somewhere in the realm of sanity..

MrS

---

Scanning for our furry friends since Jan 2002

When we can expect such such optimized apps for GPUGRID?

If it is posible for MilkyWay it must be possible for GPUGRID.

---

POLISH NATIONAL TEAM - Join! Crunch! Win!

The problem is not the optimization but the multiplication. An ATI card in double precision cannot perform better than Nvidia in single precision.

gdf

Ok, so is it possible to make for GeForce such optimized apps using CUDA?
(4-2 times faster then current aplication - appropriately so as for MilkyWay users do for Ati cards - or aplication witch will generate 4 times more credit
Is it impossible here for GeForce?)

---

POLISH NATIONAL TEAM - Join! Crunch! Win!

And 2 images:

GPUGRID:

MilkyWay:


It is clear that at the beginning of the June when an optimized program was published the project doubled its computing power and the scoring

---

POLISH NATIONAL TEAM - Join! Crunch! Win!

Thomasz,

GDF and his tam are actually very good at optimizations and have been caring about this for a long time. At Milkyway the stock code was terribly inefficient - that's why they released it, to get help from the public. So the problem is not that GPU-Grid does not have an "optimized" app, the problem is that MWs stock app is not yet optimized enough. And that they base they credits on CPU computation time compared to seti (the old standard), not flops.

At GPU-Grid you can already get more credits per time from your nVidia card than at seti, because GPU-Grid is more optimized (and may have more GPU-friendly code).

The rapid increase of RAC you're seeing at MW is not due to the release of an optimized app, it's actually the point when Travis (MW commander in chief) decided to let the work generator run more frequently, so that all the ATI cards wouldn't run dry any more but actually get new WU when they requested them.

MrS

---

Scanning for our furry friends since Jan 2002

In the end, the credits are meaningless. The only way to have any concrete gain from distributed computing is to run folding@home for the Evga team and you can get EVGA Bucks to contribute to the purchase of an EVGA card.
I like the challenge of optimizing the system to run faster but in the end the point totals only exist to encourage people to participate. 10 points a day and 100,000 point per day are really the same thing.
The real bonus is that the computations are going to help medical science or astromomy or mathematics.

At GPU-Grid you can already get more credits per time from your nVidia card than at seti, because GPU-Grid is more optimized (and may have more GPU-friendly code)

The cuda 2.3 drivers and dll's make it possible to obtain more credits per time than GPUgrid or very close to the same.
I'm getting a crazy ~10 credits per minute on my single gtx core 216 which works out to about 14000 RAC

Bob

In the end, the credits are meaningless. The only way to have any concrete gain from distributed computing is to run folding@home for the Evga team and you can get EVGA Bucks to contribute to the purchase of an EVGA card.

You imply that "not being meaningless" equals "concrete gain", something which you seem to define as "getting something of material value" (or something like that).

For me I'd say I get lots of concrete gain due to DC. It's a hobby, I can enjoy spending time on it whenever I want to (and other duties permit it). That's nothing to touch, but it's a very real "gain" for me.

... but in the end the point totals only exist to encourage people to participate. 10 points a day and 100,000 point per day are really the same thing.
The real bonus is that the computations are going to help medical science or astromomy or mathematics.

The credits also reflect the amount of contribution. Therefore they also exist to show people how good their systems are at what they're doing.

You're right that just by itself 10 or 100,000 credits don't mean anything, as it could be any arbitrary number / scaling factor. However, there's not just one of these numbers. The different amounts of credits enable comparisons between systems and projects (how valid these are is another question) and 10 credits do not equal 100,000 any more when your co-cruncher gets 1000.

MrS

---

Scanning for our furry friends since Jan 2002

Explain me this paradox...

857-GIANNI_BIND001-0-100-RND8741_3
Approximate elapsed time for entire WU: 31806.654 s
Granted credit 5664.88715277777

460-GIANNI_DOPc-0-25-RND4727_1
Approximate elapsed time for entire WU: 29039.251 s
Granted credit 6379.86834490741

In my opinion, for the longer counted WU more points should be granted.

Assuming that the second WU was awarded correctly, scoring first is lowered.

---

POLISH NATIONAL TEAM - Join! Crunch! Win!

Which has what to do with "ATI vs nVidia GPUs"?

MrS

---

Scanning for our furry friends since Jan 2002