H100i fluid/cpu temperature difference

Hello!

Yeah something seems to be a little off when looking at your temperatures.

I've got an i7 920, a very hot CPU even at stock speeds, running 4,01GHz @ 1.272 volts and my idle core temps at the hottest core are 47-50 degrees C.

All power saving features are turned off.

Corsair Link software shows H100i Temp around 36-39 degrees when idling, depending on the fan speeds I use which are around 700-900 rpm. I'm still searching for the sweet spot for idle cooling.

When running Prime95's In-place FFTs with 8 threads, my temps go as high as 73 degrees at the hottest core and H100i Temp rises to steady 42 degrees while fans are spinning 1700 times a minute. So yes, there is definitely something wrong with the transfer of heat away from your 3770k.

In my mind, H100i is a bit tricky to install because the backplate moves before you start fastening the pump.

If I were you, I would reinstall the pump unit. Of course you will need to apply new thermal paste (and take care to properly remove the old one). The single most important thing to remember is to cross tighten the nuts. And the nuts must be reeal tight.

I believe this is normal.

Just because they are at 80degC does not mean the coolant will reach that temp. Just think about it....80degC is very very hot to touch and if the coolant was that hot, you will not be able to touch the pipes or the radiator.

The reason the coolant is cooler than the die is that the die is way smaller than the rad and the heat is rapidly taken away by the rad which is massive in size relative the die.

The cores die is a tiny chip around 1 sq. cm and the rad size 336 sq. cm that's a ratio of 1:336. Another words, the die temp is concentrated in a very small space.

My i7-3770k hits 89-90degC max on Prime95 and one of the rad pipes feel warm to touch as the coolant temp reaches 36degC.

When running p95, my cpu temps are shown to be upper 80s C while the fluid temps never cross 30 C as shown in CorsairLINK. Is this a problem with my seating or thermal paste application? I'm running stock clock, and my 212 evo I had before this definitely kept temps down more. Any assistance would be advised.

your coolant will never reach your cpu temps,,if they were to then its time to worry.

your rad must always be cooler in order to keeps the cpu cool.the cpu can instantly reach high temps and will always be higher for this reason

I refuse to believe that his h100i operates normally. If you guys don't believe me, just look at all the reviews around the Internet. Temperature are way lower everywhere.

There must be something wrong with either the fans or the pump.

How fast is your pump rotating, and how many volts is it getting? What about your +12V line, what is the real voltage there? And how about the fans, whats their RPM? How do fans react when you start P95?

I refuse to believe that his h100i operates normally. If you guys don't believe me, just look at all the reviews around the Internet. Temperature are way lower everywhere.

There must be something wrong with either the fans or the pump.

 

How fast is your pump rotating, and how many volts is it getting? What about your +12V line, what is the real voltage there? And how about the fans, whats their RPM? How do fans react when you start P95?

Pump is at ~2200 rpm so normal, does voltage matter if pump is operating properly? The fans don't speed up because my profile's next coolant temp breakpoint is never reached. I'm going to try adding washers to the backplate tomorrow and I'll update to see if it makes a difference. How thick/what kind?

If the pump head is secure to the CPU you DO NOT need to add washers to the mounting bracket. That was for an issue where certain MB would not allow the pump to tighten up .

Additionally you DO NOT want the screws real tight. They will break if they are tightened too much. Run them down all the way and then just snug them up good.

At any rate I think a re-seat is in order....The pump is running right where it should be.

does voltage matter if pump is operating properly?

Absolutely not!

Also check your back plate…..yea I know it sounds silly but I made the mistake and after re-examined my install found that I had not attached back plate correctly. Instructions don’t mention to make sure CPU bracket bolts and back plate notches must aline. It just says attached plate and line up holes. I googled H100i back plate issues being loose and found this issue. I checked my back plate and found that I didn’t install correctly. Back plate will still be loose but not as bad if notches aren’t correctly lined up. Then re-seat your CPU and H100i pump and check temps. I used TX-4 thermal paste and my temp are great.

See pic of back plate.

Also check your back plate…..yea I know it sounds silly but I made the mistake and after re-examined my install found that I had not attached back plate correctly. Instructions don’t mention to make sure CPU bracket bolts and back plate notches must aline. It at all just says attached plate and line up holes. I googled H100i back plate issues being loose and found this issue. I checked my back plate and found that I didn’t install correctly. Back plate will still be loose but not as bad if notches aren’t correctly lined up. Then re-seat your CPU and H100i pump and check temps. I used TX-4 thermal paste and my temp are great.

 

See pic of back plate.

This was part of the problem, but while my temps have lowered a few degrees, they haven't hit acceptable levels for this cooler in my eyes. As a quick test, I applied pressure to the cooler block while running p95 and my temps dropped ~20 degrees. I guess this means i need to put washers to the back plate... I'm a little unhappy

Ok so updates: I put washers on the backplate and boy did that fix everything. I hope to help future purchasers of this product, so I'll list some relevant information.

MB: Gigabyte Z77 X-D3H (Gigabyte boards said to be loose with backplate = confirmed)

CPU: 3770k

27 C idle, 50 C full load w/ P95 stock settings.

Time to OC again! The product is great minus the apparent incompatibility with my MB