Although SPCR recommends
ASUS Radeon 6850 "DirectCU", I've read many reviews
that don't consider it quieter than your average stock graphic card. How should I interpret this? Is it because other reviewers are measuring noise level the wrong way, or lack sufficient cooling in the rest of their systems?
It's often very difficult to compare different reviews: just as a very personal opinion, TechPowerUp! is one of my favourite sites and to me it's a trustful reviewer with reference to performance and power consumption, but I almost always disregard their noise measurement as their noise baseline is too much high, and their equipment - meant for environmental monitoring and analisys and with a noise floor of about 19-20dB - seems not well suited for measures under a 25-30dB level (even if that B&K SLM is very, very expensive), which is by chance similar to the old SPCR SLM (the new ACO mic is well under 10dB of noise floor): you may also give a read to SPCR documents and talks about their anechoic chamber.
Apart of SPCR, the only web reviewers that currently I personally trust (so, again, it's just my humble opinion) for noise are two german ones: Au-Ja! and moreover HT4u.
With reference to the Direct-CU: I'm not a fan of the ASUS cooling solution, and maybe the TechPowerUp! remark is due to the fact it's actually a bit louder than reference design at idle. However, it seems to me a pretty decent stock cooling solution, and a well above average card.
Another 6850 very well regarded among SPCR forumers is the Sapphire one (even the standard version, not just the vapour-chambered Toxic), and due to some talks about it now personally I tend to prefer this latter over the other 6850s in the wild.
About cooling, usually silencer-oriented rigs tend towards higher temperatures, so less cooling power due to less airflow.
However I don't think it's just a matter of cooling, those differences in sound measure: the subject is more complex, I mean.
Aneon wrote:Also, do you think the PSU CoolerMaster Silent Pro M700 will be quiet enough? Or is the Corsair AX 750W notably quieter? Unfortunately, my local stores don't have any of the Seasonic models.
Well, the Silent Pro is highly regarded up to mid-low power levels (at least 200-220W, the ones you should face with your proposed setup) so I think it's quiet enough. The smaller M700 should be as well as the M850 and you may spare even more (and gain some more relative efficiency).
The Corsair is just better for noise, particularly at mid-high loads, and for its efficiency and electric performances, and all come for about 30-35% more money.
In a widely open case like the proposed Antec it might be clearly preferred, but I'm sure the CM won't make at all any poor impression (its quality is high)!
Last but not least: if you go for Noctua for your cooler, check if the shops have the C14 instead of the D14, as the former is more flexible and it should be also noticeably quieter and maybe more effective than the latter. About the installation, personally I'm not worried about, Noctuas are very well regarded for installation ease.