What's holding me back?

[TrojanWhore]

Hi, recently went from an H50 (first model) in push pull, to 'proper' watercooling, but I seem to be getting higher temps than I expected.
Some parts weren't the best of the best, and I think some part of the spec might be why it is not performing as desired.

in the current heatwave (28-30 ambient), I have been seeing around 60 degrees in games (skyrim mainly), and around 35-40 idle

My loop is as follows:

(photos/long overdue build log soon)

the top rad is a HWLABS gts-stealth (30mm, high FPI)
bottom is the mayhems quad pass I won on these very forums last month, 64mm thick, and low FPI (cheers guys!)

since I've installed this, one of the arctic PWM f12s died (the bearing makes a loud clicking at anything over 700rpm!), and as they are obviously not great Rad fans anyway, I thought it time to replace the pair.
I've purchased 2 akasa piranhas from the MM, which I still need to install, but I'm wondering if this is the issue.

my theories so far are as follows:
- the arctic PWM fans are terrible, and especially with one limited to low speed, are making the top rad redundant, or possibly even having a negative effect, due to the air heated by the mayhems rad passing through it.
- the loop order is at fault, for similar reasons to above
- my puny pump is not up to the job of pushing through two radiators
-.......or it could just be a bad mount!
- my expectations are very wrong for this kind of weather

basically I would like to hear your thoughts, as I appreciate that all the factors may be effecting performance, but would appreciate some hints as to which is more likely (before I drop £100 on a pump I don't need yet!)

also, is the piranha/apache combination good enough, or do I just bite the bullet and buy 4 GTs?

I'll be adding my next GPU to the loop, when the next gen arrives (or the one after), but would prefer to wait a while before buying a pump if I can help it.

Thanks,
Trojan

 

[eddyr]

What oc/volts are you running? If it's a high oc those temps seem decent considering the ambient.
Anyway could be a contribution of pump/GTS stealth. Id try the fans first but with 2 rads even poor heat dissipation would be offset somewhat by the raddage -unless you are running them extremely slow, turning them up will show if that a factor to any serious degree
I suspect the restriction of the block and rads may be a perf limiter, but you may not need extra pumping power (even though, I believe, the xspc have quite low head pressure) just try removing the GTS stealth rad and see how it goes on the mayhems rad and new fans.

 

[TrojanWhore]

it's running a very quick and dirty 4GHz, set the voltage at the smallest positive offset available, just because I thought this would be less prone to wild voltage swings than 'auto'.....next time I'm allowed to take some holiday I'll get the volts down a bit.

to put it in some sort of perspective, my h50 was maxing at about 63-65.(obviously this was in colder weather) the first day I tested the loop, prime got it to 43 degrees (in 15 mins or so, was pushed for time)

I shall try to find time to install the fans this week, and hope that, combined with cooler ambients, makes some difference.

PS: Eddyr, if you come back this way, are you really running at 1.6GHz?

 

[james_2k]

you are complaining about 43c?

apparently radiators offer low flow resistance, its more waterblocks etc that slow flow rates. im sure one pump should be enough for two radiators.

 

[Mynight]

I think you'll find its the ambient temperature causing it.

My idle and load temps are up by 8c in this "heat wave"

The 540 appears to be quite low powered you might suffer with a gpu block as well

 

[eddyr]

you are complaining about 43c?

apparently radiators offer low flow resistance, its more waterblocks etc that slow flow rates. im sure one pump should be enough for two radiators.

If I recall correctly the BI stealth series were one of the few high restriction rads compared to others although there looks to have been several versions (I have been assuming the old type) and the xspc pumps head pressure varies on model (unfortunately a quick google doesn't reveal any pressure/flow data for either rad or pump, this is about the closest pumpwise http://martinsliquidlab.org/2013/01/20/xspc-x2o-750-dual-bay-nylon-reservoir-pump/4/) and seems to be fair to considerably less than something like a 10w ddc's. But the 15 min prime temp would suggest that whatever the xspx450 is capable of, it is handling it fine.

it's running a very quick and dirty 4GHz, set the voltage at the smallest positive offset available, just because I thought this would be less prone to wild voltage swings than 'auto'.....next time I'm allowed to take some holiday I'll get the volts down a bit.

to put it in some sort of perspective, my h50 was maxing at about 63-65.(obviously this was in colder weather) the first day I tested the loop, prime got it to 43 degrees (in 15 mins or so, was pushed for time)

I shall try to find time to install the fans this week, and hope that, combined with cooler ambients, makes some difference.

Load of 45c on prime but subsequent temps of 60c at gaming loads (even after factoring a ~10c higher ambient) suggests that the initial prime test @45c might have stabilized higher, which would lead me towards rad dissipation being the limitation in which case the fans should help. Hard to say, there is a lot of guesswork, best way is to see what happens.

PS: Eddyr, if you come back this way, are you really running at 1.6GHz?

Yup ^^ mostly for giggles as I'm not doing anything demanding of late,and I wanted to see how low I could take the volts! Plus it keeps it nice and cool and quiet