!!!WARNING!!! The S1 R2 requires modifications to be installed on the r5770 Hawk, see below and please ensure proper contact between the thermal surfaces!
In part by the recommendation of another SPCR forumer, I picked up an MSI r5770 Hawk to replace a Powercolor 5750 Go! Green (passively cooled) which would not run stable at stock frequencies in my system. I am pleased to say that this very high-quality card is 'quiet enough' provided you keep the fan speed set to less than 20-25%.
I do not have the hardware or environment to provide objective measurements but let me describe where my judgment of 'quiet enough' comes from:
- I am an amateur musician with bat ears and experience engineering recordings
- I live out in the country in an otherwise silent room
- System specs:
4x blend of noctua and nexus fans running <800 rpm
4x Samsung EcoGreen 500 GB HDD (the ones reviewed on SPCR at ~15 dB)
Intel C2D E8400 (3.2 GHz/1.04V; <39/58C core temps idle/Prime95 passively cooled)
Seasonic x650 Gold (passive; fan never turns on in my system)
Antec P-183 (~25C ambient)
My system is quiet enough to be only barely audible over the blood rushing through my ears in my silent room. It's so quiet that I can hear my watch ticking from a meter away and my keystrokes become excruciating if I don't put my headphones on, which is exactly the way I like it. The MSI card, AT IDLE, makes no noticeable contribution to noise at fan speeds below 20%.
However, by default the fan auto-speed settings bottom out at around 35% which is quite audible. You must modify the settings in software to silence the card completely.
In my case, the card idles at around 48C (ambient +23C) with 15% fan, and maxes at 65C (per my settings) with fan speeds of 45%-60% depending on load.
However, in my estimation the electrical performance of this card greatly exceeds the thermal performance of the manufacturer provided cooler. The card easily achieves 950 MHz core clock at or near stock voltage (reference freq for 5770 is 850). I currently run the card at 950/1.18V which is at least 12-hour stable in Furmark. However, at 100% load the fans scream to keep the core temp below 65C . I don't like things getting much hotter than this, and I am too afraid to run on this stock cooler with the voltage bumped any higher, although I did briefly test at 1 GHz /1.25v (!!!). I estimate it would probably go to 1.05 GHz with the right cooling, to achieve nearly 25% increase over stock.
So I am considering aftermarket cooling solutions to improve thermal performance with the aim of lowering noise under load conditions and possibly increasing overclock performance. Because the card is not the reference design, there are many questions. I will be updating this thread as I discover the answers:
1. Are the mounting holes the same as 5770 reference?
If not exactly the same, they are close enough.
2. Will the Accelero S1 R2 or Scythe Musashi fit on this card?
The S1 R2 fits on this card with no clearance issues whatsoever. It fits so well it's a shame there isn't a double DVI post on this card
However, I did run into two issues during installation that required modification to the cooler's mount.
As you can see from the picture, I installed ramsinks on the chip-side of the card. The black plastic shroud on the S1's mount overhangs the ram on this card just a little bit, and if you install ramsinks there, will need to be trimmed away with your implement of choice.
The second problem you will have is much more annoying. It has to do with the boneheaded system of mounting the cooler. These plastic spacers are required to keep the metal "feet" of the cooler mount from contacting the card. Unfortunately, the spacers are too tall and prevent the thermal surface from contacting the GPU! They need to be trimmed down about a millimeter. I trimmed them using a razor blade and needle-nose pliers, and then sanded them down for smoothness.
In the process of ensuring solid contact, I had to trim the spacers and re-mount about 4 times. (I have used Arctic Silver's Ceramique due to its thickness, non-conductivity, and favorable thermal transfer characteristics above 50C compared to MX-2.) You would expect, as I did, that these spacers would be made of a flexible material like silicone, but in fact they are hard plastic. I don't know why Arctic Cooling would design it this way, but it limits the compatibility of the S1. This may be a reason the 5770 isn't listed as compatible.
Ultimately, I was able to achieve a good fit. After a day of playing around with Afterburner and observing thermals, I have arrived at 980MHz/1.214 V which causes the GPU to hit 61C under load (around 65C in furmark). I was able to achieve a stable RAM overclock of 1320 MHz with the addition of the ramsinks. For a silent cooling solution, I have to say these numbers exceeded my expectations. I briefly tested it as far as 1030 MHz/1.3 V, which hit 72C load. This is a phenomenal overclock for a video card.
Ambient temp in my case at the time of testing was 25 C. GPU idle temps are around 38C.
The whole rig fits beautifully in my P-183; I have mounted a noctua @ 780 RPM on the middle drive bay, which blows intake air directly over the S1. This may be contributing to its fantastic performance. Next week I will experiment with direct-mounting a PWM fan on the S1, but when the passive performance is already so good, I almost don't feel like bothering.
Here is a chart relating GPU core voltage to clock speed on this card. These speeds are stable with no artifacting or fishyness in the atitool artifact scanner (judged by my eyes, not by the scanner, which doesn't always catch everything.)
GPU Core (MHz)Vddc (V) Î”Tã€€â„ƒ Ambient Core â„ƒ
790 1.000 31 23 54
825 1.037 32 23 55
850 1.065 34 23 57 (reference 5770 freq)
875 1.100 35 23 58 (stock freq)
900 1.125 35 23 58 (reference voltage?)
925 1.149 37 23 60
950 1.174 38 23 61
975 1.214 40 23 63
1000 1.275 47 23 70
1010 1.312 49 24 73
1015 1.350 52 24 76
As you can see, between the range of 875 - 975 MHz, maximum stable core frequency approaches 1:1 parity with core voltage (1 MHz per 0.001 V). Efficiency is rapidly lost above 975 MHz; the point of diminishing returns is somewhere just below 1 GHz.
On the bottom end, MSI Afterburner does not allow the voltage to be set below 1.000V, so undervolters will have little cause to set the card below 790 MHz, the maximum stable frequency at that voltage.
The cooling performance of the S1 R2 holds up well in completely passive configuration, keeping the core temps under 65 right up until about 980 MHz/1.225V and achieving a cooling efficiency of just over 40C above ambient.
3. In case I go with the Accelero, what is a good quiet PWM fan suitable for use on GPU coolers?
I'm looking at the Scythe KAMA Quiet 120mm PWM Cooling Fan but I can't seem to find many reviews of PWM fans here on SPCR.
4. Are PWM case fan headers electrically compatible with the VGA card PWM fan header?
According to a post below, they are indeed compatible. I may or may not experiment with a quiet PWM fan, but the passive performance of my setup is already so good there's not much point.
If anyone can provide answers to the above questions, your effort will be greatly appreciated.