Re: [AMBER] 4x GTX 980

From: James Maier <>
Date: Sun, 16 Nov 2014 23:16:18 -0500

**Please note that all experiences I've cited are for GTX 780s.

On Sun, Nov 16, 2014 at 11:13 PM, James Maier <> wrote:

> Hi Parker,
> For the case, you can't go wrong with a HAF or almost anything with a fan
> on the side. We went with the "Thermaltake Overseer" for our cluster; it's
> a bit cheaper than the HAF and has a built-in SATA dock. It's a pretty neat
> case.
> Not that it matters, but the blue lights look exquisite against the green
> GTX logo.
> We actually moved the fan that's pre-installed on the front to the side,
> and put this "bgears b-Blaster" fan in the front instead:
> 120 mm, 103 CFM, not too expensive. We've not had any problems with them
> so far after about 9 months.
> As for the GPU, we've found the reference blower design to be more
> effective when trying to squeeze four GPUs right next to each other. I
> believe the blower style can generate higher (negative) pressure or
> something, because the ACX, while great on its own, seems to do a terrible
> job when something's directly occluding it. Our ACX GPUs were also higher
> clocked though, so that's an important caveat to anything I wish I could
> tell you more definitively.
> But don't take my word for it; consult some BitCoin mining forums---they
> seem to know all about this stuff. I believe a forum like that is where I
> first read something about the reference style being better for >2 GPUs,
> which seems to match our experience.
> As Scott has cautioned, "superclocked is a 'super' way to get inaccurate
> results." Sticking with a normal clockspeed will likely save headaches,
> esp. as the 980s are a new design.
> The other concern is power; you need a power supply with a rail with
> enough wattage for all cards or with separate rails that all can drive a
> card. I'm not sure if there is a single PSU that can "technically" (on
> paper, following all stats to the letter) drive four GTX780s (require 42
> Amps each, I've only been able to find +12v with 133.3 Amps, plus about 5 V
> through each PCI slot). If someone knows of an adequate PSU, please correct
> me.
> In that regard, the GTX 980s look promising due to their lower power draw.
> There are only 2 issues I can think of atm:
> (1) 980s are "provisionally" supported by AMBER. This may not be an issue,
> and according to there's an optimization coming.
> (2) 980s are immature and thus the silicon is not likely as stable as,
> say, a 780 or a Titan.
> I'm guessing Ross, Scott, or anyone who has gotten their hands on some
> 980s can chime in more about the above points.
> HTH,
> James
> On Sun, Nov 16, 2014 at 9:28 PM, Parker de Waal <>
> wrote:
>> Hi Everyone,
>> I apologize for the off topic post, however I'm currently building a 4x
>> GTX 980 machine and was wondering if anyone had experience or insight on
>> picking a proper case/fans. I'm worried that 4 cards will lead to
>> overheating in most traditional cases.
>> Additionally I'm wondering about the different fans on the GTX 980 cards,
>> specifically the reference fan blower vs. the ACX 2.0 fans on the EVGA
>> cards.
>> Any insight would be extremely valuable.
>> Best,
>> Parker
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Received on Sun Nov 16 2014 - 20:30:02 PST
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