Experiences with Aerocool VM-101 and FX5900 Ultra

[Inexplicable]

I thought I'd report my experiences from installing an Aerocool VM-101 on a Gainward FX5900 Ultra Golden Sample, one of the most power hungry video cards available today. Gainward has its own dual-fan single-slot cooling solution. Loud as hell, but supposedly quieter than nVidia's reference cooler. The gainward cooler is said to be fairly effective, so I was a little curious how the VM-101 would compare against it.

Installation is fairly straightforward but requires a little bit of dexterity. It helps to have large hands. The gainward card had two extra holes spaced a bit wider apart than the usual mounting holes. I used those, although I don't think it makes a difference. The heatsink base sits quite solidly on top of the GPU and the heatsink itself is not nearly as shaky as it looks in the pictures.

I had no clearance problems, even with a Zalman flower cooler, although the heatsink comes close to touching the ram modules on my IS7-E mobo. The fx5900u is a very long card, and this is probably not a problem with anything shorter. The zalman is blowing air into the VM-101, which seems like a nice touch.

I can tell you it's pretty important to pick the right screws for attaching the heatsink base to the card (doh!). I went as far as to try screwing in the top part before finding out that two of the remaining screws were too long. The thing about the silvery thermal gunk is that getting it on your fingertips is probably the quickest and most convenient way fry anything you touch. I must have cleaned my hands at least half a dozen times taking the cooler apart again, swapping the screws, and reassembling it with all the goop in place. Somehow I managed it without smearing it all over the circuitry. This was a first for me so chalk that one up to inexperience.

One minor nit is that the two screws required for attaching the decorative back cover were missing. Luckily they are common enough and it was easy enough to find a couple that fit. Still, a strange omission.

The stock Gainward cooler has large front and back plates that cover the ram chips, which is a bit of a bummer, since the VM-101 doesn't come with ramsinks. However, the BGA ram chips can take pretty high temperatures and seem happy enough without any cooling whatsoever. Odds are Gainward's single piece heatsink was keeping them warm instead of cooling them.

However, the only thing that matters in the end is performance. And I have to say I was pretty impressed:

idle: 42C -> 59C
load: 102C -> 93C

I was a bit worried when I saw the increase in idle temp but when I tried it a load the results blew my socks off. "Load" was not really a maximum stress scenario but I used the same one for both coolers. I used a scene from Max Payne 2 in pause mode, running in a WineX window at 1280x1024 under Linux. I gave it an hour to work up the heat. The new temps were measured after a few days when the thermal compound had had time to settle. Initial temps were a couple of degrees higher. For comparison, emergency GPU throttling temperature is set to 140 C by default. My ambient temperature is around 20 C.

My case is an Antec Sonata with the single stock fan running at 5V. I have rigged an unrestricted front to back airflow path by removing the front floppy drive bay and converting it to an intake. This arrangement seems ideal for the VM-101 as it pushes plenty of cool air right where it is needed.

All in all, for a completely passive heatsink those temps seem truly remarkable. I think the VM-101 is simply one awesome cooler. While it can be used with a lesser video card, its true power becomes apparent when installed on top of a power hungry monster like the FX5900 Ultra. I wouldn't hesitate to try this beast on a 6800GT either. I have been using this cooler for three weeks now, and have experienced absolutely no stability problems or artifacting. I haven't tried any significant overclocking but the Gainward runs completely stable in "Enhanced mode" (GPU 470 MHz, Mem 890 MHz).

Minor omissions aside, like the missing screws and no ramsinks, I can heartily recommend this cooler for anyone who thinks power and quiet should go together.