MA790FXT-UD5P CPU Coolers - a warning and advice needed

[mark rumsey]

I'm building a system around the MA790FXT-UD5P motherboard with an AMD PhenomII X4 955 processor. Although I don't intend overclocking (well, maybe a little, but not lots) I want a decent cooler as my case is a little congested, so I bought an Arctic Cooling Freezer 64 Pro V2. This is a triple U heat pipe unit with a large fan that is rated for 140W processors, so should be plenty big enough for the 125W PhenomII. I have just been laying things out ready to fit and have discovered that if the cooler is installed the correct way around so the fan blows through the fins towards the back of the PC (the bottom fins are angled to help cool the voltage regulators) the fan overhangs the last memory slot making it impossible to install anything in that slot. The cooler will fit on backwards, but it will then blow against the flow and will end up heating the case. So, anyone with this board, be careful when choosing a cooler.

Now, part of the reason I bought the cooler was I expected the standard unit suppiled with the processor to be a pretty basic lump of alloy with a fan just about up to cooling the CPU in a standard system. To say I was surprised to find a compact 4 heat pipe unit packed with the processor is an understatement. What I would like to know is if anyone knows how well these AMD coolers work. Is it good enough for a mildly overclocked system in a congested case or do I need to find another cooler? Anyone got any recommendations? I can't use water cooling (no room) and the case I'm using doesn't have any side vents. Here's a rundown of what I've got.

19" rackmount case turned on its side to create a very deep mini towe case (think full tower on its side and you're about right). In the front section of the case I've got a 3.5" floppy, SATA DVD/RW with BluRay, SCSI2 CDRW, 2 x SCSI2 CDRoms, SCSI2 Zip Drive & front panel ports. Between the front and rear is a set of three 120mm fans mounted across the case pushing arir from the front to the rear. In the rear section is the motherboard and associated bits & pieces (more on this in a moment), the PSU (850W Corsair), 1 SATA HDD, 2 SCSI2 HDD & 2 SCSI U320 HDD. The motherboard and processor are as above. Installed8GB on the motherboard is 8GB RAM (4x2GB Corsair DHX DDR3 1600MHz), a Gigabyte HD4670 512MB PCIe graphics card and an Adaptec AHA2940U2W PCI SCSI card. Possible future additions include a TV capture card, sound card (if the onboard sound doesn't do what I need) a maybe second graphics card in CrossfireX mode. It will get mixed use with some games (most of the stuff I've got is old, but I might get some newer stuff now I've got a proper 3D card), lots of web browsing, some virtualisation and some audio and video editing, and chances are it will be doing some of these concurrently.

Thanks for the help.

Mark

[Badbonji]

Can you not turn the fan around to blow to the back still? The aftermarket coolers generally are always better than the stock heatsink, but the stock might be ok for a mild overclock, due to each person's case flow being different and such you have to try it and run prime95 or similar whilst keeping an eye on temperatures. Looks like a pretty decent setup, but I would advise going CF with those cards as it is usually better to get a stronger single card vs two weaker cards, like a HD4870 instead in future. Also the next series will be out later this year.

[oggmonster]

Yeah if possible use your artic cooler, you should get a better overclock and cooler temps with that. Like Badbonji said, you could try a mild overclock with the stock cooler, run prime95 and run a temp monitoring program like coretemp (not sure whats best with AMD chipsets). If temps get too high looks like you will have to use your artic cooler

[mark rumsey]

Thanks guys. Unfortunately I can't do anything with the fan. It looks like a custom job for this cooler (see here) and I'm not sure I can mount a standard fan to it either, but I'll look into it. A standard fan should be shallower and therefore should not foul the memory. I might have found one that will move almost two thirds as much air again as the Arctic Cooling fan (67cfm against 40cfm) which features PWM control, so it should still be pretty quiet unless I'm working the processor hard.

I've done a little digging on the stock cooler. It is made by AVC and looks similar to this one from Asus. The main differences are the fan (70mm instead of 80mm) and it has a large copper base in contact with the processor with the fins mounted directly to it allowing heat transfer both via the heat pipes to the fins and directly from the base to the fins. The pipe arrangement is also slightly different, but the basic concept is the same with the heat pipes looping back into the tops of the fins. This is certainly better than I would expect of a stock cooler and I suspect AMD might be hedging their bets with the 955 Black Edition processor to make sure it doesn't overheat too easily when overclocked a 'normal' amount, that is as much as most ordinary users can manage using automated overclocking tools (like Gigabyte MIT or EasyTune).

What I think I'll do is run up with the stock cooler for now at stock (or near stock) speeds, then swap the cooler over later once I either sort the fan problem or find a narrower one.

Thanks again for your help.

Mark

[Badbonji]

That's a shame, hopefully it won't limit the overclock so much and good luck. Don't forget to keep us updated on the overclocking

[mark rumsey]

OK, I've got the system running at stock speeds and its pretty impressive. I've done a little experimenting with overclocking the processor by changing the multiplier and made it to 19.5 times (3.95GHz) without any issues using EasyTune 6 (the latest version from the website, nit the slightly iffy version supplied with the board), then noticed the temperature beginning to climb, so went back to stock. there wasn't any real change in performance, but then I would't notice as I wasn't really doing much at the time. However, overclocking is something I'll be looking into more later on. for now, I want to get it reliable at stock speeds with everything I need loaded on.

I've had a good dig in EasyTune 6 on the temperature controls and found it defaults the alarm limits to 40°C (104°F) with the auto fan speed control set for minimum speed (31%) at 20°C (68°F) and hit full speed at 65°C (149°F), which means at the alarm temperature the fan is running at about 60% speed, which means probably no more than 50% cooling capacity (air volume). These two settings seem to be in conflict. why put the alarm at a level where about half the cooling is available, or why set the fan take so long to ramp up to speed if the alarm level is a critical temperature? I'm also not sure the alarm is right anyway as currently the CPU is running at 42°C (111°F) with the fan flat out and the energy saver turned on running the CPU at a reported 32watts instead of the default 50watts. The system temperature is a couple of degrees (at most) lower and the room I'm in is probably around 35°C (95°F), which to me says the cooler I have isn't doing too badly to keep it to the temperature it is and even one of the big coolers probably wouldn't do that much better. So, what I would like to know is what is an acceptable working temperature for the PhenomII CPU if I'm going to ensure it remains reliable? My old Athlon XP2000+ usually ran around 60°C (140°F) and that is still in good condition after nearly 8 years of service.

[mark rumsey]

Anyone got any suggestions on maximum temperatures?

[runn3R]

I think it was answered already here:
http://forum.giga-byte.co.uk/index.php/topic,367.msg1734.html#msg1734

[mark rumsey]

It was indeed, and I started that thread after my last post here gained no replies.