Broadwell with Crystal Well eDRAM cache
2 Jun 2015 20:53:23 UTC
Topic 198115
(moderation:
Today Intel released Core i7-5775C and i5-5765c. Besides the new and slightly improved Broadwell core in the more energy efficient 14 nm process they both feature the fastest Intel GPU yet with 48 EUs, accompanied by a 128 MB Crystal Well eDRAM cache for CPU and GPU. This cache should help a lot at Einstein, I suppose. Does anyone have them yet and can provide some numbers?
The chips are expensive for sure, so it would be nice to know the exact benefit.
Review at Anandtech, sadly without OC.
MrS
Scanning for our furry friends since Jan 2002
Broadwell with Crystal Well eDRAM cache
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Sorry, I don't have any experience of these new CPUs, but your post made me curious about how relevant CPUs (even the ones with iGPUs) are to people.
My experience is of the (now old) 4770K and its iGPU, and it totally underwhelmed me. In fact I no longer run CPU or iGPU tasks since I consider them a waste of electricity compared to "real" GPUs.
These new CPUs will cost a lot of money. Current ones seem to go for around $250 - $350 and the new ones will probably be more expensive.
Compare that to the brand new GTX 980 Ti which is very energy efficient and practically a GTX Titan, goes for around $650.
Sorry for ranting and hijacking the thread but am I missing something fantastic about CPU / iGPU computing?
RE: Sorry, I don't have any
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Yes I think so, some people do not have the option to upgrade to a fancy gpu, they must use what they have, so having a faster cpu or igpu app makes crunching better for them. Not an option could include not owning the pc, as in a business environment. At my old work we could crunch at night, but NOT upgrade the pc to crunch more efficiently with a fancy gpu. In the end even the night time crunching was stopped because they made a deal with local electric company to cut the usage so they didn't have to build a new sub-station. Essentially the electric company paid my old work to NOT use the pc's after 8pm.
You are of course right in
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You are of course right in the way that GPUs provide a far higher throughput than CPUs. But even modern ones can only process a minority of algorithms efficiently. For all other ones CPUs are still kings. That's why you should never crunch tasks on CPUs which could also be done well by GPUs. A few projects offer this.
My CPU cores are running WCG, helping cancer research in some way. That's something my GPUs couldn't do, so rather than letting the cores idle I let them work over there. The credits are negligible compared to GPUs and even other projects on CPUs, but that's OK as lon as I feel I'm crunching something truely valuable. I wouldn't spend too much on the CPU just for WCG, but go as far as choosing a nice energy-efficent i7 Quad (3770K currently).
And the iGPU: if one gets it anyway, why not use it? At Einstein we had the situation where using the Intel iGPU would slow down the regular GPUs. In this case the additional throughput is not worth it. My GTX970 runs GPU-Grid and I have it set up carefully for maximum performance over there. It costs me 2 physical cores, but that's OK.
And with the recent BRP app improvements the performance hit from using the iGPU should have been reduced. I don't have precise numbers for this, though, as too many things changed at once on my side.
Regarding the power efficiency of the iGPU: the throughput of my HD4000 is not that much (13k RAC), but the additional power consumption is also small, between 15 and 20 W at the wall for the old app (with higher CPU usage). Trying to measure this more precisely and with the updated app one has to be careful not to change any other CPU load. And not to change CPU clocks & voltages. Anyway, the energy efficiency seems to be roughly on paar with regular GPUs. The new Broadwells would increase the performance significantly and also the energy efficiency.
This doesn't mean one should buy them instead of regular GPUs. But if one is buying a new system anyway or wants a high performance CPU anyway for other tasks, then these might be worth the price premium. Depending on how good the new chips really are.
MrS
Scanning for our furry friends since Jan 2002
Sure, if someone else pays
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Sure, if someone else pays the bills or you already have a CPU and don't mind paying yourself, CPU crunching makes sense.
I guess my point was more in regards to buying new CPUs for crunching.
Since the CPUs mentioned in this thread only really improves the iGPU compared to the previous generation I guess people reading this forum would buy them for iGPU crunching?
Why would Boincers (is that a word?) spend $300 - $400 for a new iGPU when a high end GPU costs $650?
RE: Sure, if someone else
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I'm guessing because there are still projects out there that do not have gpu apps yet. NO most do not have igpu apps either, but some do I think. For instance if you want to crunch looking for the cure for Malaria they do not have an igpu or regular gpu app, so crunching as fast as possible on a new broadwell cpu would make perfect sense.
Right now I am spreading my cpu cores out over several projects but am mostly doing WCG also. I am working on my 4th 5 year badge of the currently 5 available projects. But I have a Linux machine I am trying to get working like I want, I am not a Linux guy, that is using both cores for Malaria. I am also doing 2 other smaller projects that get 1 cpu core off this or that machine. And of course due to the hardware I am using to crunch with I also have over 10 cpu cores not crunching but are just feeding that hardware.
Logforme, I hope you did not
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Logforme, I hope you did not read my post as "people should buy Braodwell C for Eisntein", as it was certainly not meant this way.
My point is people buy CPUs for whatever reasons, and some people buy high performance CPUs. One also needs them to run GPUs. So if one is buying a CPU anyway, it may make sense to choose one which is also good for BOINC. With "good" depending on how much you value CPU and iGPU throughput, of course.
If all you want to do is crunch Einstein BRP tasks - get a box with a Celeron and 2 strong GPUs, no question. But if you also want to search for gravity waves and consider a CPU like the i7 4790K (which is a pretty strong one), you might want to reconsider and choose the i7-5775C instead.
So what exactly is the benefit of these new CPUs? How much does the eDRAM help CPU crunching? How much lower is the power consumption? How does it fare overclocked? Those are all points I'd like to find out.
MrS
Scanning for our furry friends since Jan 2002
Even WUProp does not yet have
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Even WUProp does not yet have any of them :/
MrS
Scanning for our furry friends since Jan 2002