Time to ask for some advice re. parts + setup

[Ketzer7]

So now that most of the hardware for this build I'm working on is coming together, I need some opinions and feedback on whether what I have planned is ideal and right using the parts I have picked out.

In the new build, there's going to be 3 basic things that need to get WC'ed.

- Core i7 CPU
- eVGA Classified mobo (using EK full board block)
- 2x Radeon 5870 GPUs

I'm going to be using a T3 and I'm building all of this into an ABS Black Pearl that I'm modding to fit two rads in the bottom section.

Now on that point, I had been planning on going with 2 480 (120x4) type rads. Originally, I had been leaning towards two of the new Black Ice SR-1s, but then thought about going with 480GTXs instead. Although there haven't been any test results on the SR-1s yet (hint skinnee :) ) they seem like they should have enough cooling power to handle what I've listed above, but not sure.

I tried using the PSU calculator with just the CPU, mobo and GPUs selected, but unfortunately, there's no entry for the 5870 yet. So instead I picked two 4870X2s which is sort of like a 5870 I guess. In any case, using that, I got a total TDP of ~718W.

So my question is basically are 2 low FPI 480 rads enough for all that equipment, or should I look at using the 480GTX which can dissipate a lot more if necessary? I certainly think the SR-1s or something comparable (e.g. XSPC 480, TC 480, etc.) would be enough, but just looking for a second opinion..


My other question is what should I put in which loop, or does it even matter?

I had originally been planning on putting the EK Classified block in the same loop with the CPU, but then I saw a lot of recommendations on here where people said to put chipset blocks in the same loop with the GPUs. Considering the T3 isn't really two physically separate loops, I'm not sure if it makes any difference at all which loop the chipset block goes in. I thought maybe with the CPU and chipset block in one leg, and the two GPUs in the other it might balance out restriction more evenly flow-wise. Thoughts?

Thanks all in advance.

[millertime359]

I think that if you want to compare temps of the 5870, you would want to pick a 4870. A 4870x2 is effectively 2 GPUS. I wouldn't think a 5870 would put off more heat than a 4870x2.

You shouldn't need 2 GTX 480s. 2 120x3 low FPI rads would be plenty.

I asked Martian about spliting things on the T3 and it seems you biggest concern is equalizing the restriction in both loops. So seeing that the CPU block will be the highest flowing (guessing a HK3.0?) and the chipset block being lowest flowing. I would do CPU MB GTX 480 on 1 sup loop and the other GTX480 and GPUs on other.

[Ketzer7]

Hey MT. I thought the same thing about substituting the 4870X2 for the 5870, but here's what was strange.

I originally tried substituting two 4890s in place of the 5870s on the power calc, but even at 100% TDPs for everything, it said the total power output was only ~414W (I got about the same number using two 4870s as well) which couldn't be right because I saw 5870 Crossfire numbers that showed like 664W output:

http://www.anandtech.com/video/showdoc.aspx?i=3643&p=26

So when I used two 4870X2s instead, like I said, I got a more realistic TDP of ~718W, which seemed a little more accurate to me.

Based on those numbers I just wanted to make sure my total rad capacity is enough to cover that, ideally at a 5C delta, though I guess a 10C is fine as well..


As for the loops, yes, was planning on an HK 3.0 LT. From HESmelaugh's reviews, the HK was like ~1.78 GPM, and the EK Classifieid block was like ~1.12 GPM iirc. Not sure what two 5870 blocks will be, but you were thinking along the same lines I was already, and were equalizing the restriction in both loops as much as possible. The following

T3 -> CPU -> MB -> Rad1

T3 -> GPU1 -> GPU2 -> Rad2

Seemed like the best equalization of the two off the T3. So I'm glad I was on the right track there at least. :) Thanks!

[millertime359]

Well, can never have too much rad. ;) I looked that over and it is basically the same peak power as GTX285s in SLI. You would be fine with 2 low FPI 120.3 rads. The GTX480s will ofcourse be better.

Can you fit both GTX480s? They are not suppose to be bad rads, but if you were wanting to run slower quiet fans, the low FPI rads preform better under the slower fans. If noise isn't a concern, than you can't go wrong with with those GTXs from what I hear.

The balancing doesn't have to be exact, but it sound like you really don't want one sub-loop flowing at 1.7 GPM and the other sub-loop flowing at .7 GPM.

[Ketzer7]

The case has a width of ~210mm, so as best I can tell going with the high end of rad thickness of 60mm, I figure I can fit two in the bottom standing on their sides with 25mm fans mounted:

(2 * 60mm) + (2 * 1mm) + (2 * 25mm) = ~172mm

leaving 38mm between, so should have just enough clearance for fittings and whatnot.


Going back and looking over skinnee's data on triple rads, you're right, MT.

He showed a figure on the 5C delta graph of about 314W dissipated on a TC 120.3 rad with 1800 RPM fans. Times 2 would obviously mean a total TDP of slightly north of 600W which is already close to what I'm calculating for the output of the parts that will be under water.

I don't know if there is a straightforward calculation to extrapolate the dissipation possible on a 120.4 rad from a 120.3 measurement, but it's definitely going to be more by some value. So even going by a worst-case total heat output of like 700W, something like two TC 120.4s should be more than enough to keep a 5C delta at full load using even -15 GentleTyphoons.

I guess those numbers were for the older 25mm hole spacing version of the TC though, weren't they? Is there much of a decrease from those numbers going to the newer 15mm versions?

Since the GTs are currently out of stock, I had been thinking of giving some 120x25mm San Aces a try, the 9G1212H401 model:

http://db.sanyodenki.co.jp/product_db_e/coolingfan/dcfan/dc_fan_detail.php?master_id=2421

They officially undervolt to 6V, but if some of the old and new tests of San Aces I saw were correct, I'm betting they can even start as low as 3-4V. Their static pressure isn't too bad and neither is their full-power noise rating. No one's ever tested them though, so I'm not sure about them.

In any case, thanks for the feedback, I think I'm set now planning to use two TC 120.4s for everything.