I pitted 4 new P3 coolers against the Intel retail unit this week. Two are from USA-based RDJD who seem to be cranking out a variety of thin-fin designs lately. The other two are from Ultracool, one with a slight modification..
UltraCool are the people who made the original twin-fan unit upon which the SuperDual Socket370 is based. I wasn't particularly enthusiastic about this new P3 cooler from them because it looked as though it would suffer the same problem as the other unit - basically, looking great but having a weak fan. The fan on the P3 cooler is a strange 80mm one made from translucent plastic with curved blades that look almost like flower petals. This sits on top of a beefy-looking blue-adonized aluminium heatsink which has vents to allow for airflow over the L2 cache chips. This sells for AUD$35.00.
Looks like Tom from pccoolers.com had the same feelings as me about the default fan on the UltraCool unit. Given the success of the SuperDual conversion he has taken it upon himself to improve the unit above by replacing the fan with an 80mm Sunon unit kicking out 35cfm. This fan also has a 3-wire connector so you don't lose the rpm-monitoring capability. This sells for AUD$45.00 as the "Mega 80mm P3 Cooler".
This unit looks like an extended version of their K602 Socket370 unit. The same thin-fin design with a thick aluminium plate for a base and the same strange 52mm fan. I'm not sure why RDJD insist on using these fans instead of a more common 60mm unit. These seem to be louder but not that impressive in the air-moving stakes, and, being such an odd size, would be tricky to replace if they ever died. The base is vented to allow air to cool the L2 cache chips. This sells for AUD$35.00.
This looks identical to the P301 above. In fact, I had to log onto their website to see what the difference was. Turns out this unit has "an embedded copper plate" for better thermal transfer. Well, it's embedded pretty well because I can't find it anywhere, and the unit seems to weigh exactly the same as the P301 which is odd - you'd think the presence of a chunk of copper would make it noticeably heavier than the all-aluminium one. Anyway, I guess we'll trust the website for now.. This sells for AUD$35.00.
So how do they compare? I tested them on a P3-450 at 504 for about 15 minutes of Q3A action. I've included the retail unit's results for comparison. I tried all each unit with the fan reversed also, to see if this made an improvement.
Well, the RDJD units show themselves to be quite respectable if not spectacular. The P302 is about a degree cooler than the P301 so it appears there really is a difference between the units. The fan RDJD uses is loud though, there's a definite low-pitched buzzing sound. Given they're the same cost as the standard UltraCool unit which is better and quieter, it's hard to recommend them.
Reversing the fan didn't have a positive effect on any of the units, noise or cooling-wise.. There's some wind noise from the big fan on the modified UltraCool, of course, but it's a fairly unobtrusive hiss - and the cooling performance is very impressive. In fact, even in standard form the unit offers surprisingly good cooling. If you wanted to go for the big monster (another for the clear perspex case?) the modified UltraCool, or "Mega 80mm P3 Cooler" as it's called on the website, is probably a pretty good buy.