Brute force TEC air cooling for AMD CPUs – Joe
SUMMARY: Brute force TEC air cooling for AMD CPUs.
The kind folks at Swiftech were nice enough to send a sample of their latest heatsink, the MCX462+T ™ Thermoelectric heatsink for AMD ® CPUs. This is one hefty heatsink – it features
- 226 Watt Peltier (15.2 volts)
- 1/2″ thick copper base
- Motherboard socket hole mounting
It weighs in at almost two pounds. It is bolted to the motherboard through the four holes around the socket, using spring-loaded bolts. Once tightened up, correct pressure is applied to the CPU.
I tested the Swiftech with Vantec’s Tornado, a Sunon 80 x 38mm fan, model #PMD1208PMB1-A rated at 84.1 cfm @ 5700 RPM, 55.2 dBA, 9.1w; this fan features vanes in the base to straighten airflow off the blades. I measured¹ its noise at 75 dBA with a Radio Shack sound meter 8″ from the fan’s intake – very loud. It can not be used with a motherboard fan header.
The base is very well finished:
Flat bases are a Swiftech trademark. The TEC is held in place by 8 bolts which are visible around the base. Mounting pressure for a TEC should be something on the order of 80 – 100 lbs, so an assembly such as this is required.
In summary, a beefy copper base / aluminum pin heatsink with a 226 watt TEC.
The MCX462+T ™ was first tested on the CPU Die Simulator which gives results that are unaffected by motherboard influences. I then tested it on a Shuttle AK31, modified to read AMD’s on-die diode, as an example of what users might see on their systems.
To power the TEC, I used a Thermaltake 420 watt power supply – this gives 216 watts at the 12 volt rail. TECs run best at something like 70-80% of full power, so running at 12 volts is OK. A 15 volt dedicated power supply is not cheap.
I also measured Cold Plate Temps – Swiftech kindly bored a small hole on the side of the plate to embed a thermocouple over the CPU.
Cold Plate Temp
|MCX462+T ™, 69.4 watts|
|MCX462+T ™, 99.6 watts|
CPU Die Temp
Cold Plate Temp
|STRESS: XP @ 1467, Shuttle AK31|
|IDLE: XP @ 1467, Shuttle AK31|
¹In-socket thermistor per MBM
Swiftech’s site has a performance graph showing temp results for different CPU loads. On the graph below, the Blue Xs are the results I attained (tables above) compared to Swiftech’s:
Note that my test conditions are very close to Swiftech’s and that the load temps I found track very closely. The notable discrepency is what I achieved under IDLE conditions; this is not at all surprising, but does point out that users will most likely show better results, as the average PC is not 100% stressed all the time.
It also points out that insulating the socket is of prime importance, as below ambient temps are very likely in the “Optimal Operating range”.
Results I found are consistent with Swiftech’s claims. Compared to other non-TEC assisted aircooled heatsinks in the Heatsink Ranking, the MCX462+T ™ obviously outperforms them.
I takes a LOT to deliver an effective, aircooled TEC heatsink for an AMD hotty. Swiftech’s MCX462+T ™ is an excellent example of what it takes – almost two pounds of metal, a 226 watt TEC and an 84 cfm fan.
Thanks again to Swiftech for sending this our way.
¹Note that manufacturers measure fan noise usually 3 feet from the fan.