My goal was to better understand the impact of adding a second 360 radiator, which in theory doubles the heat dissipation capability of your loop. But what does it bring to the table in terms of overclockability on the AM3 platform?
Read on for a lightweight comparison between running one and two 360-sized radiators in a single loop, cooling a quad core AMD Phenom II CPU………….
TEST SETUP
Liquid Cooling components
Radiator(s): 1-2x Alphacool Nexxxos Xtreme III rev. 2
CPU block: EK-Supreme Acetal
Pump: Swiftech MCP655-B
Reservoir: Magicool 400mm POM tube
Tubing: Masterkleer 12,7/15,9mm
Fittings: 13/16mm compression
Radiator fans: 120x120×25mm push/pull 7.9v
Coolant: Pure distilled water
Loop order: Pump -> Radiator(s) -> CPU -> Reservoir
PC hardware & software
Motherboard: Gigabyte GA-MA790FXT-UD5P (BIOS f3m)
CPU: AMD Phenom II x4 965 BE (rev. C3)
RAM: 2×2GB OCZ Platinum (1600MHz 7-7-7 1.9v)
GPU: 2x XFX ATI HD 5770 1Gb (rev. 1)
PSU: Chieftec CFT 1200G-DF 1200W
Software: Windows 7 Ultimate 32bit
CPU-Z v1.53
Prime95 v25.9
HCI MemTest v4.0
Core Temp v0.99.5
MAX stable OC
single radiator
Below are a CPU-Z screenshot of the highest achievable OC using a single 3×120 radiator. Prime95 blend test was used for load and stability testing.
4116MHz CPU (1,55v) & 2940MHz CPU-NB (1,50v)
I finally settled for a CPU frequency of 4116MHz, together with a CPU-NB running at 2940MHz. With a load temperature of 51C°, there is no headroom left to push things further.
And as expected the dual radiator setup had no problems at all with this heat load.
MAX stable OC
dual radiator
CPU-Z screenshot of highest achievable OC using dual 3×120 radiators connected in serial. Stability where once again confirmed with the help of Prime95.
4158MHz CPU (1,55v) & 2970MHz CPU-NB (1,50v)
With two radiators connected in serial, it was possible to push the frequencies even further. Managed to squeeze out 4158MHZ for the CPU and 2970MHz on the CPU-NB.
With temperatures shooting over 52C° before crashing, the single radiator setup just couldn’t to handle this kind of heat load.
QUICK FINAL THOUGHTS
Moving from a single to dual radiator setup allowed for a small but respectable increase in frequency. To be precise, an extra 42MHz on the CPU and 30MHz on the CPU-NB. Not too shabby at all in my opinion! ….
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Very nice test!
Not a bad drop as it seemed to be about a 5C drop in everything with the 2 hooked up.
I wonder if you had 3 hooked up if it would get you any closer to ambient and if it would keep with the about 5C drop.
Yea, was pretty surprised about the difference as well
But fans where run at low speed, and guess that should have a bigger impact on a single rad… Need to play around some more with the fan setup!
Very informative, I was searching information regarding PII 965 temps on water..was thinking of upgrading my rad to a triple ones..
I’m running PII 965 @ 3.8Ghz with a dual 120mm crap Alu rad, low speed fans in push pull config: 34 Idle, 45 load.. I’ve pushed it to 4.1Ghz but its unstable on P95..strange because previous owner ran it under single stage cascade..around 5+ Ghz…probably these chip loved low temps,and mine already used to subzero lol..I guess anything beyond 50 will cause instability..or a rapid temp increase..
THanks for the information, my 1055t was able to push to 4g on air with d14, so i think i might able to push to 4.2 with dual rad, will try it out, thanks again !!!!
Maybe you should just put a car radiator next to your computer.