Athlon64 3500+/3800+ @ x86-secret.com (http://www.x86-secret.com/popups/articleswindow.php?id=105) ( article in French ).

Even if you don't understand French, you can still look at the charts to see that the S939 offers a healthy performance increase compared to the S754 parts.

Only downside is a very noticeable increase in power consumption ( a Prescott-like 104w ) & heat output ( 50°C idle / 60°C full load ).

I saw this a little while ago. Dunno why I didn't post it... but I wasn't as impressed with the performance increase over 754 as I thought I was going to be :(

Well the 3800+ does perform as planned.;)

The 3500+ (s939) is a bit disappointing as it comes out slower then the 3400+ (s754) in some circumstances.

BTW it could seem Cool'n'Quiet wasn't activated which explains the high idle temps.