Guidance for building a folding dedicated computer

[ollie1983]

I will probably stick with an Asus Sabertooth X99, I have had a range of Sabertooth MBs in the past and they are unstoppable and are designed for the grief.

I am not well versed in the latest CPUs, is the 6850K with it's 6 cores going to be a good choice for folding, does the client take advantage of them? My current i7 3820 seems to rock along nicely about 65 degrees quite happily.

Assuming we can stretch to 2 1080ti, what PSU do you guys think I should get? I am a fan of corsair/seasonic, just need to know how much watts to spec. 850-1000 I am guessing?

And whilst we are at it, what case will fit all of the above in and a good slew of case fans? I haven NXZT Phantom for my current PC and I am tempted to get a second.

Thank you for the help so far.

[Leonardo]

A 750W PSU will serve you well for a dual-GTX 1080Ti rig running Folding.

Assuming you will not be folding with the CPU, a 4-core CPU will work every bit as well as a 6-core CPU. If you will be GPU folding, I wouldn't even bother assigning a slot to the CPU. It's not worth the extra power consumption.

[ollie1983]

I was intending to let the CPU do some work as well, as it only consumes a measly 140 watts.

With that CPU and 2 1080ti what sort of PPD are we likely to achieve? I would like to nudge 1 million if possible?

[jrweiss]

You may as well go for a 1000W PSU. The 2 1080ti's will take 500W, the CPU brings it to 640, and MoBo and accessories will take 20-50W more. You'll be in the "sweet spot" for efficiency on a 1000W PSU.

[Nathan_P]

Another point regarding the PSU is that a 750w unit might not have enough cables for the mobo and dual gpu's. X99 usually needs 2 eps 8pin cables and then you need 2 twin PCIe cables

[Leonardo]

Sure, consider the PSU recommendation jrweiss gave. But, given "sweet spot" (efficiency or not), I doubt the efficiency will ever compensate for the higher purchase price of a 1000W unit over a 750W unit.

I was intending to let the CPU do some work as well, as it only consumes a measly 140 watts. With that CPU and 2 1080ti what sort of PPD are we likely to achieve? I would like to nudge 1 million if possible?

If your electricity is free, then sure, why not fold on the CPU. Seriously, CPU production is trivial, absolutely trivial, compared to high end video cards. Save the money and get a modest 4-core CPU. ('Trivial' is my opinion, obviously.)

A dual-GTX 1080Ti system, not GPU-overclocked, should produce *1.7 to 2.1+ PPD, depending on the assigned work units. If the second video card's PCI-e slot performs at better than PCI-e 4X, the upper range should be more common than the lower range.


*There will be some flyers - WUs that occasionally produce far less than they usually do on the same system.

[Aurum]

I will probably stick with an Asus Sabertooth X99, I have had a range of Sabertooth MBs in the past and they are unstoppable and are designed for the grief.
I am not well versed in the latest CPUs, is the 6850K with it's 6 cores going to be a good choice for folding, does the client take advantage of them? My current i7 3820 seems to rock along nicely about 65 degrees quite happily.
Assuming we can stretch to 2 1080ti, what PSU do you guys think I should get? I am a fan of corsair/seasonic, just need to know how much watts to spec. 850-1000 I am guessing?
And whilst we are at it, what case will fit all of the above in and a good slew of case fans? I haven NXZT Phantom for my current PC and I am tempted to get a second.
Thank you for the help so far.

That's a sweet MB. The comment about having extra CPU socket pins is interesting. https://www.asus.com/us/Motherboards/SABERTOOTH_X99/
With a 40-lane CPU like your i7-6850K you'll be able to run a dual 1080 Ti at x16x16 and later when you add a third 1080 Ti at x16x16x8. This CPU with fast RAM should do you well when you're gaming. This CPU has 12 cores and you need to dedicate one or two per GPU to support GPU folding. The other 8 to 10 cores can fold their own WU. This a fine CPU to meet your dual gaming/folding needs.
I'd go with something like a Corsair AX-1200, that's about all I use. That way you can easily grow to the full 3-slot potential of this MB. No need to stretch, start with a single 1080 Ti and add a second and third later.
If you use a case be sure it has space on the edge of the MB with the third graphics slot so the card can hang over a bit and breath. I build my rigs open air so they cool better and are easier to clean.

[SteveWillis]

If you are not folding on the cpu you do not need anything better.

I've seen it mentioned many times that for GPU folding the CPU doesn't make a lot of difference. I thought I'd mention that I just over clocked the CPUs on two of my three rigs and my overall PPD immediately went up about 5%. I would imagine that a faster CPU would have the same effect.

[toTOW]

On Windows, I've seen more influence of CPU power than on Linux ... and mostly on smallest proteins.

[foldy]

That is interesting: Is it only the Mhz or also the CPU architecture?
e.g. a Core2Quad with 3,3Ghz has the same speed as a 2500k with 3,3 Ghz for GPU folding PPD on Windows?
Or Is a 2500k@4,5Ghz faster than a 6700k@4,0Ghz for GPU folding PPD on Windows?
Is it Nvidia GPUs only because of the spinning wait or also AMD GPUs with idle wait?

[QuintLeo]

Intel CPUs for a pure folding rig tend to be overpriced when they have enough performance to handle the load.
AMD FX series are a lot lower cost for the same number of cores, and get the job done fine while costing a LOT less and being able to use motherboards that ALSO cost somewhat less.
For comparison on recent rigs I've built - Intel G4600 DUAL CORE + MB + RAM cost about the same as my more common AMD FX6300 (*6* core) or AMD FX8320e (*8* core) on the same basis, while offering A LOT LESS ability to keep up with 3 GPUs or even 2 TOP END GPUs in a single rig.

Ignore "hyperthreaded" cores - they do NOT work well to support folding GPUs, they MIGHT be worth a QUARTER of a real core.

Go NVidia - GTX 1070, GTX 1080, GTX 1080ti are all fairly close on performance/$ when you factor in the entire system.
The GTX 980ti (and possibly the GTX 980) is a fairly good choice if you can afford the higher power usage and you can get one inexpensively enough, but the 980ti NARROWLY outperforms the GTX 1070 while using 2x or so as much power, or slightly underperforms the GTX 1080 while using half again or a bit more power.
The GTX 1060 has fair performance, but current pricing with the "cryptomining craze" has inflated it's pricing to where it is NOT competitive with the higher-end Pascal cards on a hash/$ basis.

DO NOT do "riser rig" type construction like used in cryptocoin mining. The 1x PCI-E channel will KILL your performance.
If the slot doesn't have AT LEAST 4 physical PRI-E lanes it's worthless for folding, and anything less than 8 on a PCI-E 3.0 connection or 16 on a PCI-E 2.0 connection will cost you a little performance.
A 4 lane PCI-E 2.0 slot will cost you ballpark 10% of the performance of the card, anything LESS is going to be a lot worse.

Anything less than a GTX 1080ti/Titan (possibly the GTX 980ti as well), figure on allocating AT LEAST one PHYSICAL core per GPU.
The GTX 1080ti, figure on a core and a half to 2 cores.
My short-lived rig with a pair of GTX 1080ti running on a dual-core Intel G4600 (Kaby Lake 3.5 Ghz) WAS CPU LIMITING NOTICEABLY on both GPUs
The GPUs performance on the SAME projects went up a LOT when I moved one to a FX 8xxx based rig, despite having PCI-E 2.0 8 lanes instead of PCI-E 3.0 16 lanes for the slot and having to limit the TDP a little due to cooling issues.

Ignore Vega - the benchs I've seen so far indicate that the Vega 64 is BARELY going to match the GTX 1070, while eating twice OR MORE the power and costing more.
In fact, ignore AMD (unless you already HAVE an AMD GPU) - lower performance, higher power usage across the board for the last 3-4 generations.

[SteveWillis]

I have a 1080 on a 2.0 1x riser and get around 620K PPD. I wouldn't exactly call that "useless".

[foldy]

The nvidia driver can only use one CPU core per GPU.
Looks like really old slow CPUs limit the new fast GPUs.

"My short-lived rig with a pair of GTX 1080ti running on a dual-core Intel G4600 (Kaby Lake 3.5 Ghz) WAS CPU LIMITING NOTICEABLY on both GPUs"
That is interesting, did anyone else had this problem with a new fast GPU but only dual core for 2 GPUs?

The pcie bandwidth limit is only a big problem on Windows. Using Linux you loose only some % and so using x1 risers on Linux is possible.

RX Vega 64 makes 600-850k PPD so that is still reasonable too but uses more power.

[Leonardo]

RX Vega 64 makes 600-850k PPD so that is still reasonable too but uses more power.

Unless your electricity rates are very low, I think that performance is not good considering the power consumption of that GPU.

[bruce]

RX Vega 64 makes 600-850k PPD so that is still reasonable too but uses more power.

Unless your electricity rates are very low, I think that performance is not good considering the power consumption of that GPU.

Some (younger) donors don't particularly care, because their college dorm pays the electric bill. The rest of us DO care about power consumption.