RDJD K601 Review

SUMMARY: Folded fin heatsinks will become more common and displace more expensive aluminum extrusion units as they are cheaper and perform better. The RDJD K601 is the price/performance alternative to the Alpha 6035 – a little less performance for a lot less price.

K601 vs No-Name

Ever since I picked up the No-name thin-fin heatsink at a computer show, I have been trying to find out what company makes these with no luck. However, RL Pierce emailed me with the URL of a company which makes a similar unit – RDJD. This is the company which makes what I tested as the best “Intel approved” PIII heatsink on the market – their P301 (HERE)..

Folded fin heatsinks are very efficient for their size and weight – this is due to the large fin surface area. The K601 packs 66 square inches in its small package, while the No-Name packs an astounding 165 square inches into its package. Interestingly, the K601 outperforms the No-Name. I think it’s because the No-Name allows air to escape off the top of the fins whereas the K601 does not.

The Test

I mounted the Alpha, No-Name and K601 on a slotket in my ABIT BX6-2. The following table lists thermal diode temps for my C366 @ 550 while running Prime 95. For this test, I let temps stabilize and then I ran Motherboard Monitor for 5 minutes, taking temp readings at 1 second intervals. Motherboard Monitor records the lowest temp, highest temp and average – in this case the average of 300 readings.

C 333 @ 550 MHz   
HeatsinkLow TempHigh TempAverage Temp
Alpha 26 cfm fan41 C47 C43.4 C
No-Name 26 cfm fan42 C49 C45.0 C
K 601 17.5 cfm fan42 C49 C45.1 C
No-Name 16 (est) cfm fan43 C49 C45.5 C

NOTE: Ambient temp 21 C, Thermal diode temps running Prime 95, Average Temp = average of 300 observations in 5 minutes with Motherboard Monitor.

K601 vs Alpha

The Alpha is a clear winner but not by a lot. The No-Name comes close but only using the YS Tech 26 cfm fan. The K601 is 1.7 C worse than the Alpha with its 17.5 cfm 52 mm fan. The 2 C temp difference is incredibly close considering the Alpha’s size in relation to the K601 and No-Name. I think Alpha and others are going to face incredibly stiff competition from folded fine units to our benefit – expect prices to come down markedly and performance to go up.


Tweaking the K601 is more difficult than the No-Name due to its 52 mm fan; You can replace the No-Name’s 60 x 15 mm fan with a YS Tech, but not so for the K601. I’ve been thinking of some kind of ducting arrangement for the K601 to use a higher cfm fan, but this starts to get into a lot of work for not so much gain. Hopefully RDJD will upgrade this unit to a 60 mm fan and this will open more possibilities.

In the meantime, the RDJD is a very credible alternative to the Alpha, especially for Coppermines (less demanding re heat). Its compact size makes it perfect for the “space-challenged” motherboards on the market and hopefully we will see more performance oriented versions of these units shortly.

NOTE: Alpha is coming out with a new version of the socket 7 unit and we will be reporting on it as soon as we get it.

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