Besides the perfect finishing, another good thing is installation. The SLK948-U requires a custom pack plate. This means you'll have to remove the motherboard out of your case, to get to the backside of it.
Not so with the Swiftech MCX6400-V, all you need to do is remove the top part from the retention bracket. Then place the heatsink on the CPU, put the screws with the springs through the holes and tighten them. Piece of cake!
The MCX6400-V™ is designed to be used without AMD®'s retention frame, but necessitates the backing plate for its installation.
The spring loaded mechanism provides a safe and effective attachment method to the motherboard, and complies with AMD®'s static load specifications.
Some people had troubles with the helicoid pins at the outer edge of the heatsink breaking off, but I didn't experience any such problems during (de)installation. Just remember to handle this heatsink with proper care.Let's heat up the sinks !
the tests were run on system outside the case
Piotke's Test Setup
|CPU ||AMD Athlon 64 3000+|
|Mainboard ||Shuttle AN50R|
|Cooling ||MCX6400 & Boxed cooler & SLK948U|
thermal grease was some no-name white stuff
Three different 80mm fans were combined with the 3rd party heatsinks:
SANYO 80mm 109P0812M701
Airflow: 20.13 CFM
Noise: 21 dBa
Nominal speed: 2000rpm
Delta 80mm AFB0812SH
Airflow: 46 CFM
Nominal speed: 4000rpm
Delta 80mm FFB0812EHE
Airflow: 80.16 CFM
Noise: 52.5 dBa
Nominal speed: 5700rpm
As the boxed cooler was designed for 72 mm fans, I didn't change that one.
A64 3000+ @ 2000 Mhz @ 1.45 Vcore
First I tested these heatsinks, by using the default speed and voltage from my A64.
Once again, keep in mind that ambient temperature was about 30°.
The sound level from the boxed cooler can be compared with the 80 mm fan with medium fan speed.
With a low rpm fan, the SLK948U has a slight advantage compared to the MXC6400-V. But we can see following trend: The more powerful fan you use, the better the MCX starts performing. The difference is small, and if I would have used only one fan, there would be no clear winner. But by using three different types of fans, you can see a linear evolution....
A64 3000+ @ 2450 Mhz @ 1.7 Vcore
Now we cranked up the heat output from the CPU. Here the MCX starts trailing the competition, I installed the heatsink about three times, but it still gave me the same result. I noticed that the base was really hot, but the heat didn't seem to transfer to the pins fast enough dissipation.
The boxed cooler wasn't able to keep the CPU below 70°C, the predefined shutdown temperature I set in the bios.
Temperatures are always nice, but what does this mean in overclocking terms... I overclocked my A64 as far as possible, with both the heatsinks. The medium rpm fan was used.
20Mhz difference that is 0.8%, the temperature difference is ~11% however, the big copper base of the Swiftech gives you quite benefit when searching the limits of your CPU’s overclocked speed. The performance difference with the current top A64 cooler is very small!
Time for the conclusion ->