Old block on new CPU.

[Michelle090]

Hey everybody. I have little bit issue with my latest loop since I got myself new cpu in terms of not optimal temps. Its basic loop that cool only cpu. Also my loop have bunch of rads (semi-passive build) far as two of 3x120 (30mm) + one 1x120 (40mm)  but only 4 fans.  But running my 7700k at 4.8Ghz while on cpu heavy operations I am hitting 80-90+ temps, even recorded 100. Syntetic cpu tests trigger thermal throttling in seconds. My suspicion is cpu block itself. Its old. Old in age and design, it was custom manufactured for me way back when I was running Celeron D 3.2Ghz.  But it sucessfuly cooled 3570k oc. Did little research on topic and found out Celeron D had tdp 86W. 3570K (I had before) had tpd 77W with calculated oc tpd at 88W. But 7700k have 91W and when overclocked its cca 140W.  That is almost double for block was designed for. Water temperature is only 1 deg higher then ambient on idle and somewhere 8-10 higher with load then ambient after some time.  I think A) block is not properly mounted (checked many times) or B) block cant transfer heat from cpu to water efficiently. 

I wanna hear your what you think about that. Its time for new block? Or buy more thermal paste and try reseat it again? I think I already know my answear but asking others does not hurt  

 

Thanks, M

[airdeano]

welcome to the Linus Tech Tips forums!

 

unless the CPU block was from late 90's to 2008, that'd be a good assumption. but blocks from 2008 till today really don't vary in thermal transfer too much by 2°-3° coolant temperature. its more of an aesthetic choice. ive still got an older 2006 DTEC that is still as fresh as todays versions with only a 1° thermal difference then a todays heatkiller.

usually the issue stems from the internal construction of micro fins (today) to open cavity with a couple of fins in them.

 

i'd say your B postulate is close to what is happening. but if you are looking for 20° drop over what you have now, really wishful thinking, but not a real expectation. 

[RollinLower]

what kind of fluids have you been running with the block? maybe if you used pastel fluids it is just blocked with gunk from the fluid.

otherwise everything seems to point at the block not functioning for the high wattage. especially since fluid temps are so low, that suggests the heat isn't transferred to the fluid properly.

[Michelle090]

Its design start somewhere mid 2008, but as I said is custom made and even it is cnc manufactured and nickle plated still cant compare to professionally made blocks.  I am not hoping for dramatic temp drop, but I dont want to kill my cpu and runing it at high as almost 90 does not help it. Pic of block internals No microfins or anything fancy. Water enter in middle, leave on one side. 

I am running just simple distilled water with no other additives (colors or chemicals) water is still clean, little bit of gunk around fittings but nothing dramatic. No wonder, last time I clean it all up is more then year, haha  But that block is hard to block since it like 3mm between those "fins" and even rust once did not block it after month of brown water in it. 

[airdeano]

this might help a reference:

 

depending on overclock methods/voltages/silicon lottery your not going to improve drastically from your older block.

only four fans isnt helping much either. find some xspc 1650 fans cheap (most arent used) for $20shipped and find a decent sale on a used ek supremacy or even a XSPC raystorm and go with that for modernization. then you'll find that you might be a bit more comfortable thermally.