Haswell heat/performance tradeoff

[smbenn]

Hi All

Just building my fully passively cooled PC for audio processing (Ableton, Reason, etc). Just need assistance on the CPU.
So far rig consists of:

Case - Nofan CS-80
PSU - Silver Power SP460-FL 460W (made by Seasonic X-Series)
CPU cooler - Nofan CR-95C Pearl Black IcePipe 95W
Motherboard - Gigabyte GA-Z87X-D3H (LGA 1150)
Memory - Corsair XMS3 8GB (2x4GB) DDR3 PC3-12800C9 1600MHz Dual Channel Kit
BluRay Reader - Pioneer BDC-207DBK Blu Ray ROM/DVD RW
SSD - Samsung 840Pro 500GB [not purchased yet but reliability is my main goal. Will probably RAID-1 up later]

I've seen that Haswells generate more heat than IB and obviously wanted to avoid heat buildup (esp for the more CPU-intensive multi-threaded tasks) so was thinking either i7 4770T or i7 4770S because of the hyperthreading and performance. Or would a 65W i5 be better?

I know that the CR95C can handle up to 95W TDP but this may only be half the story. Read somewhere that TDP-limited chips can get hotter than unrestricted ones, or is that just nonsense?

Anyway, thanks a lot people.

Cheers
Simon

[edh]

Case - Nofan CS-80

Aesthetics are obviously a personal thing on cases. There should be plenty of ventilation here to allow passive running for a low power build but maybe it is worth considering a heatsink case like a HFX or Streacom instead? This has dust sealing advantages and keeps buzzing components separated from your ears.

PSU - Silver Power SP460-FL 460W (made by Seasonic X-Series)

460W is an awful lot for a system that will use maybe 100W max. You are unlikely to ever be able to expand your TDP up to that kind of power level and keep passive cooling throughout so you might as well save some money and go for a 400W PSU instead - or even a small low power PicoPSU or similar.

CPU cooler - Nofan CR-95C Pearl Black IcePipe 95W

The jury is still out on these things. Yes, they are passive and should be able to cool one of the 84W CPUs without much problem but they have a lot of physical constraints and are hugely expensive. Perhaps a Thermalright HR-22 is another option, there's a few others too. Or maybe look at a Heatsink case.

Motherboard - Gigabyte GA-Z87X-D3H (LGA 1150)

Why go for a fullsize ATX motherboard? Unless you expect to use lots of expansion cards or multiple high end graphics cards there is no point. You will slightly add to the TDP, cost and risk of buzzing components just by having something bigger. Try MicroATX instead.

I've seen that Haswells generate more heat than IB and obviously wanted to avoid heat buildup (esp for the more CPU-intensive multi-threaded tasks) so was thinking either i7 4770T or i7 4770S because of the hyperthreading and performance. Or would a 65W i5 be better?

S and T versions can be matched for TDP by simply undervolting and underclocking a standard CPU if you want to save money. In terms of i5 versus i7, what are the hyperthreading requirements of your applications? If not beneficial, an i5 is obvious. IIRC the higher TDP is partly down to the improved iGPU which may not be so much of interest to you and if you're only working on the desktop, shouldn't make a huge difference to power in use.

[smbenn]

Thanks edh for the quick response. As I've purchased all the components (sorry if I didn't make that clear!) however:

Case - matter of taste, you're right. Needed a large vented case for the CR95C, ipso facto.
PSU - just assumed a larger unstressed PSU would be more effective than a smaller more stressed but hearing what you're saying. Esp as regards buzzing etc
ATX Mobo - simply more space and more potential for the future. (say if I wanted to add more cards)

As regards the whole hyperthreading thing there definitely seems to be a good argument for it for DAWs: http://www.tomshardware.com/reviews/hp- ... 718-8.html

So how easy to underclock? Never done this before. Should I just go for a 4770?

Thanks again
Si

[CA_Steve]

If you are doing orchestral levels of VSTs, etc, then you can benefit from an i7. If you are just doing a few tracks, then you can easily use an i3. In between, an i5 would work. Then again, if you have orchestral levels of VSTs, then 8GB of RAM might not be enough.

I also recommend just getting the standard Haswell part. My suggestion would be for you to search for reivews specific to your mobo. The UD3H version of your board allows for CPU core offset voltage. Hopefully, your D3H board has the same. You should be able to set that at, say -0.1V, and be able to run at stock speeds. That can drop 5-10C off your load temps. As for underclocking, you probably need a K part to get access to the clock multiplier. All you do is set the multiplier to a value below the std and you get an underclocked part.

Here's a screen shot for the UD3H courtesy of Anandtech.


They also had a nice interview/overview of the Gigabyte boards/bios as well. Long, but there's some useful information inside.

[smbenn]

Thanks Steve. I am probably overspecing the machine (or is this just futureproofing?) as I certainly don't run a huge amount of CPU-hungry VSTs at the moment (although never say never). Will reconsider moving down to the i5.

Another stupid (but related question): can I adjust offset voltage on a non-K chip (so it's a mobo function only)?

Simon