i7 920 OC + 2 GPU's = 1 loop?

[ajcfalcon]

Ive done some research on this, and i know if i did 2 loops for what i want i would be fine. However, because of space issues i dont have room for another loop... here it goes...

I have a TC 120.3, apogee xt on my i7 920, and a MCP655 pump.

Im very happy with my temps, but my damn 4890's sound like they are going to take off!

I have 2 questions...

1) if i added another TC 120.3 and both gpu wb's to my loop (one big loop) would i be looking at high cpu temps? Wattage-wise it should be enough radiator assuming each radiator can handle 5-600 watts each at ~15* delta (on the high side) but im wondering if adding them to the same loop does that change things as far as delta temps are concerned? The graphs didnt really talk about multiple rads in a single loop so i wasnt sure how that worked...

2) will the single mcp655 be able to push the whole loop efficiently? Looking at peoples setups similar to mine, they run multiple pumps but i have seen mostly mcp355's used, so wasnt sure if the 655 would do the trick?

 

[Conumdrum]

You should be fine, about 550 watts of heat total. Maybe 250 from the CPU, 150x2 from the GPUs. Two of those rads would do well in handling the heat. A PA 120.3 does very well at 300 watts, check Skinnees again.

If your DT is xx and you double the rad your DT drops by half. Or close to it.

Flow rate? You'll have to see, probably within specs.

Give it a go.

 

[||Console||]

2 loops is just the best method , one loop will still work just fine . ( I bet you would be fine with even just your one rad i will get flamed for that but I bet the 2 4890s would only raise your CPU 5-10 deg )

I have 2 rads and a CPU and GPU my D5(655) has no problems

 

[Conumdrum]

Console is correct, you might be able to use the one rad. Your CPU temps will go up under load, hopefully still keeping the CPU below 72C or so (coretemp). I'd just get another rad, you know you want to!

 

[ajcfalcon]

Ha its true, im getting another rad regardless lol

Regular use temps (internet, etc..) my temps are around 26 - 31*C and im at 4ghz (core temps are low 40's), under load it goes up to about 40*C cpu temp and mid 50's core temps, prime95 after about an hour or so i got it up to about 76*C.

My cards run idle 67 and at 50% fan speed while gaming go up to about 82... and 50% fan speed on these bad boys is deafening.

Thanks again guys for your help!

As a side note, i have the "B" model of the 655 which i guess isnt very good from what i have been reading... where can i find more info on this? i just want to make sure im covered when it comes to flow

 

[Conumdrum]

The B model is a bit lower than the vario in flow and head pressure. You can see the specs on just about any of the sale sites. Try Sidewinders. The B runs at a 'speed' of 4, while the vario is adjustable up to 5 (from 1-5).

It's a good pump, it might be enough, I think you should be fine. GPU blocks are pretty open flow and won't restrict it much. You won't know till you try. If not enough then you could find a used 'B' or get a DDC3.2 with an aftermarket top and replace the 'B'.

Wait, your CPU cores go up to 73C after an hour of prime? With just a i7 at 4.0 in the loop your CPU shouldn't go above 65C or so MAX. What fans do you have? My i7965 at stock speeds loads at 55C or so in 2 hours of prime and my room temp is 80C. I have a PA120.3 and a ddc3.2 with an XSPC restop, but the pump makes no diff in this simple loop.

You should make a sig like most of us have.

 

[ajcfalcon]

What temp program are you using? Im using pc wizard. the "cpu temp" goes to about 67 but the "core temps" can get up there...

 

[Conumdrum]

Hehe, you pick.

Coretemp
Realtemp many like this, you can calibrate your sensors with this one. Well, calibrating the software.
HWMonitor, more measurements

All 3 of these are well regarded.

So is
CPUZ
GPUZ

Your cores are typically 5C higher than the CPU temps. We pretty much only mean coretemps, not CPU temps. Mobo software for temps really is bad.

 

[ajcfalcon]

hmm.. interesting. Well, according to Real temp it is mid to high 60's, however it is automatically bouncing my multiplier around. Thats at 2400 mhz 200bclk x 12, but then it will bounce to 200 x 20 @ 4000 mhz and my temps go to the high 70's.. i have speedstep disabled so ill have to look into this further.

What would be a cause of these high prime95 temps? WB contact?

 

[Conumdrum]

Prime 95? small ffts or a blend test? Small ffts is best for load.

Yea, that would be my first guess. What voltage you running? Not using auto voltage are you?

 

[ajcfalcon]

ok i fixed my OC, its steady at 20x multiplier, doing the small ffts its actually hitting low 80's after about 30 minutes... ill get some more paste tomorrow and reseat the WB and see if that helps.

P.S. im running 3 med speed yate loons in pull config at 1600 rpm

 

[Conumdrum]

Plenty of fannage, yea somethings not right.

When was the last time you rebuilt your loop? What liquid do you use?

 

[ajcfalcon]

Ok i just redid thermal grease, i used Arctic MX-3.. supposedly good stuff according to the guy.

Real temp core temps under prime95:

77 - 76 - 73 - 70

Much better but still not right. since they are so far off from each other im assuming im not applying the thermal grease correctly, im doing it in a vertical line like the online directions say... ? hmm

Im using distilled/silver for liquid

 

[Conumdrum]

Please make a sig like most of us have. I have no idea what CPU, what block, pump, chip etc your using. or any overclocks.
unless I scroll ALL the way up. Come on, make it easy on us too, we are trying to help.

7C diff between cores is considered okay. 10C then yes you might have a remount problem.

If you take your block off now, is there paste coming out from all 4 sides? That means wayyy to much. It really shouldn't be coming out the sides, a teeny bit if any.

Most of us use a blob larger than a grain of rice, smaller than a small pea, place it in the middle and put the HS right on top and ever so slowly tighten each corner down in a cross pattern. One turn of a screw at a time. Slow, but your sure to get an even mount.

 

[Sneaky]

A PA120.3 will handle that fine...

if you want proof, here's what I was running for 2 months:

Intel Skulltrail 2x 5420 Xeons @ 3.0ghz, 2x 4870's at 790/1100, plus Skulltrail SB

cooled by 2x Fuzion V1 CPU, 2x Fuzion v2 GPU, and Blastflow SB block, w/ a single PA 120.3 and D5 pump

Load temps for CPU's and GPU's stayed under 45C at 100% load

 

[ajcfalcon]

Just redid the thermal paste again, still high 70's - low 80's but they are closer together now. What could be the problem here?

P.S. Im actively trying to figure out how to add a sig on here. until i figure it out:

i7 920 OC 4gz
Asus p6t
6gb 1600mhz corsair xm3

WC:
pa 120.3 rad > Apogee XT > XSPC single bay res > MCP655 > rad
Primochill LRT 1/2" tubing
3 Med yate loons in pull 1620 rpms
distilled water

Case temps are 31*C

Could the waterblock be faulty?

 

[Higdon]

Under the top menu on the site is a link called "User cp" Click that. Once you go there, on the left hand side you can edit your sig.

 

[Conumdrum]

Yea, time to open the block. And why not the pump too. Not sure which way your rad is, if barbs are pointing down you could have a LOT of air in the rad, it could be only 1/4 full or something.

And I'm still curious about your voltage settings. Some mobos on an overclock pump wayyy to much voltages to the chip when on auto. They need set manually. That can be your problem.

A pic would be nice.

 

[ajcfalcon]

My cpu voltage is set at 1.35000, multiplier at 20 and bclock 200. Most of everything else is on auto, im using xmp profile

 

[Conumdrum]

Have you tried a lower voltage? Or do you need 1.35 for that overclock?

Hard to tell, you got the inlet of the block getting incoming water? There is a tiny recessed dot on the CPU block for inlet. It makes a BIG diff in temps.

If the loop is running and you remove the plug at the top of the rad for bleeding do you get air or water? Or did PA get rid of the bleed screw? Be careful, LOL, it will spurt out, you should be able to get it loose enough to check.

And there is a specific way to mount the XT, umm it has to be parellel with the chip lockdown clamp. Forget exactly, but it matters. Look it up on the Swiftech site, there is good instructions there.

You don't have a GB Mobo, so your not hitting caps like some had happen. They had to recess one side of the block for that.