AMD vs nVidia for Seti

Message boards : Number crunching : AMD vs nVidia for Seti

Author	Message
Alex Storey Volunteer tester Send message Joined: 14 Jun 04 Posts: 449 Credit: 1,357,537 RAC: 1,269	Message 1208421 - Posted: 21 Mar 2012, 11:42:20 UTC
	When I started the "GPU wars" thread, it was with this quote: "GCN would be AMD’s Fermi moment, where AMD got serious about GPU computing..." I jumped to the conclusion that these new (Graphic Core Next) cards would be far more "Seti-friendly" and that in a generation or two, Seti's Top Computers might be a mix of both GPUs instead of an nVidia monopoly. I thought new apps would have to be written for GCN and Kepler too. But now I'm not so sure... What's the dealio with these two?
	ID: 1208421 ·

Richard Haselgrove Volunteer tester Send message Joined: 4 Jul 99 Posts: 7461 Credit: 39,738,054 RAC: 34,469	Message 1208429 - Posted: 21 Mar 2012, 12:16:51 UTC - in response to Message 1208421.
	Although GCN is already in the shops, Kepler isn't yet. I don't think either of the developers has a development sample trom their preferred range yet, and I doubt that either of them can afford to buy one, either. Let alone the testers.....
	ID: 1208429 ·

Alex Storey Volunteer tester Send message Joined: 14 Jun 04 Posts: 449 Credit: 1,357,537 RAC: 1,269	Message 1208445 - Posted: 21 Mar 2012, 14:08:12 UTC - in response to Message 1208429. Last modified: 21 Mar 2012, 14:39:22 UTC
	Although GCN is already in the shops, Kepler isn't yet. I don't think either of the developers has a development sample trom their preferred range yet, and I doubt that either of them can afford to buy one, either. Let alone the testers..... Always appreciate your answers Richard, and to clarify I wasn't asking "Why aren't GCN/Kepler apps out yet!?":) Here are my questions: Do these new cards (from both) need new apps? Is GCN completely different at GPU computing, or just a fancy new name? Will GCN be substantially* better (in theory) than previous AMD cards at Seti? Does someone from nVidia have to come in (again) and rework the apps for Kepler? Why is nVidia so much better at Seti? (Is it Cuda? The architecture? Both?) I realize (most of) these questions can be answered in theory only (and that's what I'm looking for). I'm not looking for cold hard stats between GCN/Kepler. Just a better understanding of the two, always in relation to Seti. And when I say subsantially, I mean performance gains other* than those gained by a "simple" die-shrink. Edit: Also who are the "developers" and who are the "testers"? Seti crew & Lunatics crew? I have next to no idea of who does what for who and how, around here. Not a gripe of course, just stating a fact.
	ID: 1208445 ·

Mike Volunteer tester Send message Joined: 17 Feb 01 Posts: 19498 Credit: 21,193,554 RAC: 26,675	Message 1208453 - Posted: 21 Mar 2012, 15:10:00 UTC Last modified: 21 Mar 2012, 15:10:45 UTC
	First of all i dont think we will need new apps but for better performance there will be some. So far i´m concerned GCN uses different technique for calculation. so actual apps will not benefit from this architecture. Raistmer is developing the ATI/AMD apps and Jason G is for cuda optimisation. ____________
	ID: 1208453 ·

Richard Haselgrove Volunteer tester Send message Joined: 4 Jul 99 Posts: 7461 Credit: 39,738,054 RAC: 34,469	Message 1208476 - Posted: 21 Mar 2012, 16:10:15 UTC - in response to Message 1208445.
	Does someone from nVidia have to come in (again) and rework the apps for Kepler? I don't think anybody really knows the answer to that - which is why I would advocate caution until the silicon hits the tarmac. I have vivid memories of the Fermi launch, two years ago. I think NVidia knew their previous two applications (608 and 609) were incompatible with Fermi, and supplied the replacement 610 application to the project. But the message didn't get through, and the penny didn't drop, at the project end - until I applied some brute force. Beta message 39386 We think NVidia learned their lesson over that one, and stopped using sneaky optimisation techniques that didn't conform to their own programming guidelines. But we won't know for certain until... NVidia have, we think, withdrawn from collaboration with SETI now that their initial publicity objectives have been achieved (and ATI never even started collaborating, but that's a different story). So we may be in for interesting times, again. I'll be trying to keep an eye on how it develops.
	ID: 1208476 ·

Alex Storey Volunteer tester Send message Joined: 14 Jun 04 Posts: 449 Credit: 1,357,537 RAC: 1,269	Message 1208513 - Posted: 21 Mar 2012, 18:06:31 UTC - in response to Message 1208476.
	Thanx again Richard. That more than covers the nVidia app question, and the Beta thread helped me understand your comment about Developers and Testers. So here's what's left for anybody that feals like jumping in: - Do the GCN cards need new apps? - Is GCN completely different at GPU computing (compared to last gen AMD GPUs), or just a fancy new name? - Will GCN be substantially* better (in theory) than previous AMD cards at Seti? - Why is nVidia so much better at Seti? (Is it Cuda? The architecture? Both? Or, in light of Richard's new info, is it just the fact that no-one from ATI/AMD has lent a helping hand?) And when I say substantially, I mean performance gains other* than those gained by a "simple" die-shrink.
	ID: 1208513 ·

msattler Volunteer tester Send message Joined: 9 Jul 00 Posts: 34178 Credit: 345,177,292 RAC: 551,358	Message 1208517 - Posted: 21 Mar 2012, 18:11:50 UTC - in response to Message 1208513.
	Thanx again Richard. That more than covers the nVidia app question, and the Beta thread helped me understand your comment about Developers and Testers. So here's what's left for anybody that feals like jumping in: - Do the GCN cards need new apps? - Is GCN completely different at GPU computing (compared to last gen AMD GPUs), or just a fancy new name? - Will GCN be substantially* better (in theory) than previous AMD cards at Seti? - Why is nVidia so much better at Seti? (Is it Cuda? The architecture? Both? Or, in light of Richard's new info, is it just the fact that no-one from ATI/AMD has lent a helping hand?) And when I say substantially, I mean performance gains other* than those gained by a "simple" die-shrink. I suspect you are asking some questions that shall have no answer until either some users or optimizers have such hardware to test with. The Lunatics folks have already stated that they don't know if current apps will run correctly on Kepler, or if it will require another round of optimization to make them compatible. ____________ ****** "Ask not, what your kitty can do for you. Ask what you can do for your kitty." As it is kitten, so shall it be done.
	ID: 1208517 ·

Alex Storey Volunteer tester Send message Joined: 14 Jun 04 Posts: 449 Credit: 1,357,537 RAC: 1,269	Message 1209448 - Posted: 24 Mar 2012, 0:51:22 UTC - in response to Message 1208517.
	I suspect you are asking some questions that shall have no answer until either some users or optimizers have such hardware to test with. The Lunatics folks have already stated that they don't know if current apps will run correctly on Kepler, or if it will require another round of optimization to make them compatible. Yeah, I'm confusing everybody by bringing up optimizations. My questions were more about engineering/architecture. I'm going to take a long hard look at the detailed tech specs of my ION and Sten's 315m (which are based on the same chip apparently) and see if I can figure out what makes Seti "tick". Meanwhile, anybody want to have a shot at explaining why nVidia have been so much better at Seti than AMD, for the past couple of years?
	ID: 1209448 ·

msattler Volunteer tester Send message Joined: 9 Jul 00 Posts: 34178 Credit: 345,177,292 RAC: 551,358	Message 1209449 - Posted: 24 Mar 2012, 0:55:35 UTC - in response to Message 1209448.
	Meanwhile, anybody want to have a shot at explaining why nVidia have been so much better at Seti than AMD, for the past couple of years? Uhh, maybe that they stepped up to the plate early on, and gave Seti and the optimizers the tools to make it so? AMD, not so. ____________ ****** "Ask not, what your kitty can do for you. Ask what you can do for your kitty." As it is kitten, so shall it be done.
	ID: 1209449 ·

Alex Storey Volunteer tester Send message Joined: 14 Jun 04 Posts: 449 Credit: 1,357,537 RAC: 1,269	Message 1209452 - Posted: 24 Mar 2012, 1:04:57 UTC - in response to Message 1209449.
	Fair enough. But what about board design and tech specs? Was there something that gave nVidia an advantage @seti up 'till now?
	ID: 1209452 ·

jason_gee Volunteer developer Volunteer tester Send message Joined: 24 Nov 06 Posts: 4048 Credit: 60,422,070 RAC: 57,944	Message 1209472 - Posted: 24 Mar 2012, 2:22:33 UTC - in response to Message 1209452. Last modified: 24 Mar 2012, 2:35:56 UTC
	Fair enough. But what about board design and tech specs? Was there something that gave nVidia an advantage @seti up 'till now? Better software all around: app (having helped the project get started), drivers, developer tools, language & libraries, as well as a solid bug reporting mechanism with actual feedback. On the hardware side. having kept the 'programming model' (a hardware architecture term) fairly consistent since G80 has helped, with fairly rational generational extensions for new features that mostly can either be used or not, so much older code will work without modification (though targeted tuning & optimisation is usually beneficial). This means development can continually improve instead of being bogged down with major rewrites of non-critical code every time. The Cuda core 'virtual architecture' concept is a fairly potent one, that has ramifications for hardware arrangement itself, & all the described software support aspects, kindof 'unifying' everything pretty well. jason ____________ "It is not the strongest of the species that survives, nor the most intelligent that survives. It is the one that is the most adaptable to change." Charles Darwin
	ID: 1209472 ·

Wiggo Send message Joined: 24 Jan 00 Posts: 1491 Credit: 62,802,030 RAC: 87,928	Message 1209520 - Posted: 24 Mar 2012, 4:47:31 UTC - in response to Message 1209472.
	AMD looks like it'll have the edge over nVIDIA though when it comes to doing AP's. Cheers. ____________
	ID: 1209520 ·

Alex Storey Volunteer tester Send message Joined: 14 Jun 04 Posts: 449 Credit: 1,357,537 RAC: 1,269	Message 1210023 - Posted: 25 Mar 2012, 14:30:01 UTC
	850 "The Answer to the Ultimate Question of (Seti) Life, the (Seti) Universe, and Everything" It's obviously not very accurate but hey, cut me some slack... I haven't got 7.5 million years left in me to get it absolutely right:) Just take the magic number and multiply by the number given in the Relative Compute Performance column. Is the result anywhere near your GPU's RAC? Depending on your tolerance to variation, I think it might be pretty close. Funny how you set out to do one thing with numbers, and then they take you wherever they want. I was trying to decipher the tech specs of Sten's 315m GPU and my ION2, but couldn't quite nail it. Unless this new fad called ASIC quality has something to do with it, the best I can tell is that GPU core clock speed is the all important number. All else is (pretty much) equal when comparing our GPUs. Funny 'cause I thought it would be shader clock speed, but it's the same. Then one thing lead to another and hey presto: 850! Jason, thanx for the backstage Cuda report. Always appreciated:)
	ID: 1210023 ·

Message boards : Number crunching : AMD vs nVidia for Seti