Q6600 cooling - is my CPU water block to cheap?

[Mastiff]

I'm running a rig with a Q6600, Asus P5K-E and Corsair memory. I can't get stable above 3.645 mHz (FSB 405) Prime stable. I can boot into Windows with at least 3.8, and it will POST, but go into an endless loop of starting Windows and rebooting on 4.0 gHz. I have tried reducing the multiplier and increasing the FSB, and I have no problems going to FSB 480 with memory 1:1 on multiplier 6, so it's not the motherboard or the memory.

I thought I should be able to get further with water cooling. I'm starting to wonder if this is because of the ThermalTake BigWater waterblock. I have two radiators running on this thing, and 1,5 VCore (this computer isn't on 24/7, it's a HDPC and runs for a couple of hours 2-4 times a week.

The reason I suspect that the water block is holding me back is that Prime95 gets the temperature in Core Temp up to well over 60 C, and it can get up to 70 at times. But when I stop Prime95, it falls by 20 degrees within 2-3 seconds. That seems to fast for me, I would have thought it should take at least 10-15 seconds. Or am I totally off here?

This is a G0 from an early batch of those, btw. VID is 1.2750 in Core Temp.

 

[muddocktor]

Hello Mastiff, temps could definitely be playing against you there. What are you using for the rest of your loop? Like pump and radiators and tubing size and such?

I have no experience with any TT watercooling crap so I don't know how efficient (or not) the waterblocks they make are. But The Swiftech GTX wb has proven to be a sterling wb choice for Intel quads and my temps with 2 Q6600's don't get above the mid 50's on the hottest core running OCCT with them and run in the low to mid 40's while crunching Seti, both running at 3.6 GHz. I haven't tried pushing them further because I value 24/7 reliability on those Seti crunching machines.

 

[Mastiff]

Well, it's obviously a cheap set, but I was able to overclock a much hotter Prescott P4 quite a bit with the same stuff, so I'm a bit confused. Of course I do need stability too, having a crash while watching a movie isn't really an option. Which is why I'm talking Prime stable. Still I would hope I could get higher. I have tried a bit of "Norwegian extreme cooling", mainly putting the rig in my garage! The temperatures are a lot lower there, but I still don't seem to get further. So I'm starting to think that I have reached the limit of this thing. I guess not all G0's are created equal. Still it seems rather strange that the temperature falls that fast when releasing the load.

 

[muddocktor]

I see much the same when I take the load off my processors too. You have to remember it is reading from a diode in the actual core and you have an IHS and some TIM in between the diode and waterblock. I see a 15-20 C drop in temps when I drop the load off my systems too. But my temps are at a lower average temp than you are seeing, both under load and at idle (not that they are at idle much).

 

[Badbonji]

I am still using the bigwater parts (except the block) for my core i7, temps still only reach just over 70C on load. Remember this is core i7, it kept my Q9450 @ 3.7Ghz 1.37Vcore under 45C load too.

 

[bz2klag]

The reason I suspect that the water block is holding me back is that Prime95 gets the temperature in Core Temp up to well over 60 C, and it can get up to 70 at times. But when I stop Prime95, it falls by 20 degrees within 2-3 seconds. That seems to fast for me, I would have thought it should take at least 10-15 seconds. Or am I totally off here?

For what it's worth, I don't think you are totally off.
For a desktop chip, 70C is just too high.
The thermal spec is only 71C, so I would guess that something is wrong.

You said the system sees limited run-time.
I was curious, what happens to a water-cooled system when it's idle
for periods of time? Does it dry up, corrode, etc? Could you be losing
some cooling effectiveness?

 

[bz2klag]

I am still using the bigwater parts (except the block) for my core i7, temps still only reach just over 70C on load. Remember this is core i7, it kept my Q9450 @ 3.7Ghz 1.37Vcore under 45C load too.

Wow, nice overclock on your i7, but 70C seems way too high.
I'm just kidding when I say this, but you have a water-heater
that scores over 23000 in 3dmark vantage. Cool.

I am by no means a water-cooling expert, but it sure sounds like
something isn't quite right for you and the OP. Whether it's the block
or some other component, it sure seems like something isn't up to the
task of properly cooling the processors at these voltages and speeds.

I'll venture out on a limb and say that there is probabily a big diffference
between your i7 (and the OPs Q6600) and your Q9450. For one, the
TDP on the i7 is a brutal 130W, versus the 95W on the Q9450. I would
also guess that there is a fairly significant difference in current draw
for an i7 at 4.36GHz (or a 65nm Q6600 at 3.8GHz) versus the 45 nm
Q9450 at 3.7GHz. As voltage AND clock speeds are increased, the
current draw goes up perhaps more dramatically than expected.

I hope I'm not giving any bad information. I just wanted to say something
out of concern, it doesn't hurt to discuss the matter and maybe fix it
before you experience an overheat. If anyone who is more knowledgable
would like to confirm or deny what I've posted, then that's cool. I want
to learn too.

 

[jr1]

i would think you would gain some with a better block since i guess your using the ttblock with that s-loop in it
if it is that one you don't get all that much surface area for the water to pick up the heat
also you didn't mention other specs than the block
ppl that have more experience than me probably would be able to tell you more if they know what the rest of your loop is

 

[schmide]

I'm guessing you have a Thermaltake Bigwater 745. The radiators on that system are not very good being aluminum and such. A good 120.2 or 3 would improve your cooling a lot and may get you the extra heat dissipation to lower those temperatures.

I would also say 3.6 on a q6600 isn't that bad.

 

[Spawn-Inc]

i would toss out anything that has thermaltake on it (w/c wise) and build from scratch. with my loop (sig) i can get my quad benchable 4.2 and the highest i've bothered to go stable is 3.6GHz @ 1.4v