Are some Athlons cooler than others?

[Liquidity]

I have an XP1800+. I *think* I have heard that some version of the Athlons run cooler than others, even at higher speeds. Am I on crack? Ok don't answer that. I don't mind buying a new procesor (especially if it's faster) if I can find one that runs cooler.

Thanks!

-Liquidity

 

[mechBgon]

The Bartons, on a board that supports S2K Disconnect, are probably going to be the coolest-running in terms of core temps and thermal production. The Barton core is used in the AthlonXP 2500+, one of the 2800+ variants, and the 3000+, and right now the price is sitting around the $175 level for the 2500+.

 

[mechBgon]

Aha, and here are some actual numbers to go by: XBitLabs' results with S2K Bus Disconnect enabled/disabled

 

[Liquidity]

Wow that's a great article. Thanks!

Unfortunately I just bought a Shuttle SN41G2 and I don't think that board supports the S2K disconnect thing. S'ok though that article helped me understand the heat issue a little better.

-Liquidity

 

[mechBgon]

Have you looked to see? Maybe it does. I mean, I've got original nForce 1 boards at work that have it. Maybe it's in there

 

[Bloody]

Do you know if is there a list of motherboards with S2K bus disconnect support? I've read somewhere that the new chipsets support it, but what about the older ones?

As far as I know on the boards that support it this function is disabled, because of problems with the older Athlon CPUs, so any info on how it can be enabled, BIOS update or...?

 

[mechBgon]

I don't have a list of which boards support it, sorry but I thought the Barton was the first to utilize it anyway

 

[Bloody]

I couldn't find much info on S2K bus disconnect, but I believe that programs for software cooling (such as vcool) utilize it (Bus disconnect) to lower the CPU temp while Idle. I'm not sure about that because of the lack of information about S2k

With Vcool for example on my old CPU/MB setup I could reach 20+ degrees celsius temperature drop when CPU is about 0-30% (50 => 30 on Athlon XP 1600+) which is about the same temperature that xbit reported.

 

[chizow]

Great link Mech, definitely fits the title as being

I didn't even know this feature existed , but it doesn't look like its fully implemented on the mobo side of things yet. I'm definitely gonna check my BIOS when I get home from work to confirm but Xbit says:

Now the situation should change drastically and Athlon XP processors will become much cooler on those mainboards, which will support S2K Bus Disconnect. Many today's chipsets, such as VIA KT400, VIA KM400, SiS 746 and NVIDIA nForce2 do support S2K Bus Disconnect without any problems. There have already appeared the first mainboards, where the Bus Disconnect feature may be enabled in the BIOS. So far there are only five mainboards like that. They are: ASUS A7V8X v1.04, EPoX EP-8K9A2, Gigabyte GA-7VAXP v1.0, Gigabyte GA-7VAX v1.1 and Gigabyte GA-7VA v1.0. However, since they do not certify any more mainboards without the support of Bus Disconnect function, this list should very soon grow longer.

Also, it seems that this was implemented even with Palomino or T-bred, just never implemented on mainboards nor enforced by AMD:

However, Athlon XP also required System Bus Disconnect to be able to switch to the lower power consumption state. In fact, this should be implemented in the mainboard chipset and BIOS. But until recently, the BIOS of most mainboards used to be configured in such a way that Athlon XP never got to the lower power consumption state. As a result, even in idle mode the temperature of all Athlon XP processors remained pretty high.

 

[Bloody]

It has been implemented even in the older AMD CPUs, but the problem is that by default most of the motherboards are configured not to use the function, probably because of encountering some problems. And here come the programs that offer software cooling of the CPU, they simply utilize the Bus Disconnect function when the CPU is idle...

 

[Doomer]

I've got 2 AMD systems. Both are very similar, same HSF on both, same MB, etc. one is a XP1700+ and the other is an XP 2400+. The 1700+ runs about 10c cooler than the 2400+.