It's no secret to overclockers that the hot (read: cool) forced air cooler for almost any CPU is made by Alpha. Alpha has a reputation for building heat sinks that is unmatched.
I decided to test that out in conjunction with the Abit KA-7 motherboard review. Until the Golden Orbs, I'd never used a non-factory heat sink/fan combo, but after hearing stories about the Athlon's legendary heat production, I decided that it wouldn't be such a bad idea to try something beefier. So I trundled off to Plycon's web site, plopped down my $55.00 (including the Sanyo Denki fans) and patiently waited.
As an aside, kudos to Plycon. They've recently switched from Express Mail to Fedex for delivery and it shows. I ordered on Thursday and the package arrived on Monday. That's a much better showing than the nearly 10 days for the Golden Orbs.
The P7-125 comes as a kit. It's completely disassembled. The heatsink assembly is packaged in its own box and includes fairly reasonable instructions. The fans were packaged separately.
What you see is what you get: the heatsink, two fans, fan mounting bracket, screws and thermal paste.
The heatsink comes from the factory modified to fit the Asus K7M motherboard. The K7M board puts the ATX power connector a little closer to the processor slot than does the Abit KA-7, but even the Abit board's connector was a little close. The heatsink probably would have fit without modification, but it would have been difficult maneuvering around the fins.
Speaking of fins, when you assemble the P7-125, be careful. The heatsink is made out of aluminum, an excellent radiator, but it has very sharp edges and corners. Don't get too lax, or you'll find yourself scrambling for a bandage.
The fins are very large and deep, providing a lot of surface area for cooling. Also, the mounting bracket for the fans doubles as a sort of duct, controlling and directing the air flow from the bottom of the unit up and out through the fans.
Assembly was easy. All of the holes were positioned perfectly…no pushing or twisting required. The fan mounting bracket is attached with four self tapping screws that require a fair amount of effort to bite into the aluminum fins. The fans are attached to the bracket with long, self tapping screws that crank down much easier.
Now, this may sound silly, but be sure that you attach the heat sink to the processor BEFORE you install the fan bracket. This isn't really made clear in the instructions, but the bracket blocks access to two of the four screws that secure the heatsink/fan assembly to the CPU.
Also, be sure that you spread the thermal paste thinly. The idea is to use it to fill in any gaps between the heat sink and the CPU. If you just slather it on, it will perform worse than with no thermal paste at all!
Once assembled, the Alpha P7-125 is large. Very large.
Check your motherboard and case. The assembly measures 11.5cm x 7cm x 8.5cm. If your motherboard or case is tight on space, you may not be able to fit it in. The heatsink/fan fit just fine on the KA-7, and it's supposed to fit the K7M. Also, if you've slacked off and didn't install the CPU support pillars on your motherboard, don't install this heat sink until you install them first. The P7-125 is heavy, and it will damage your motherboard if it isn't properly supported.
Of course, the acid test is the operation. As I mentioned before, I tested the Alpha P7-125 with the Abit KA-7 motherboard and an Athlon 700. I intended to install the unit in a mid-tower case, but discovered that there was not nearly enough clearance between the Sanyo Denki fans and the power supply. In fact, the only case that the motherboard would fit in was a full tower SuperMicro case, and only with the 3.5" drive bay removed.
The portions of the fins that were removed from the heat sink allowed access to the ATX power connector, as well as the two fan power headers.
Initially, I installed the dealer-supplied heatsink and fan. I ran several applications, including SETI, Quake III and Unreal Tournament to make sure that the CPU was working as hard as possible.
After running for several hours in a fairly warm room, the CPU temperature was 105 degrees F and the case ambient temperature was 93 degrees F.
I turned the system off and let everything cool, then installed the Alpha P7-125. After the same amount of time had passed, I monitored the CPU temperature at 93 degrees F and the ambient temperature at 83 degrees F. In both cases, the room's ambient temperature was a toasty 80 degrees.
Obviously this means that the Alpha P7-125 dissipates a tremendous amount of heat, something that really ought to be expected. AMD states that the Athlon should never exceed 70 degrees C, or about 180 degrees F, a rather startlingly high temperature. Maybe not so obvious is that fact that with the Alpha P7, a processor that cries out for overclocking suddenly has enough thermal headroom to do so safely. Also, system in a cooler room would also probably run a bit cooler.
The Alpha P7-125 is also available in a version for Slot 1 processors from Intel.
The bottom line is that this heatsink/fan combo continues Alpha's reign as the passive cooling system king. If you have the space and the budget for a very large, premium priced cooling solution like this, or if you are determined to wring every last bit of speed from your Athlon processor, then the Alpha P7-125 is the perfect cooler for you.