In the picture above of the beta RD580 board, you can see the AM2 socket and surrounding mounting mechanism. This is another area where things have changed. Whereas before the mounting bracket was attached through two holes in the motherboard, this has been swapped out for a four hole approach. On the bracket itself, there used to be three lugs per side, but now there is now just a single lug. Then on either side of this lug, on the outside edge is a catch which I assume some coolers will be able to take advantage of.
The lugs are still in the same position as they were on Socket 939, so many coolers will still fit this mount and for anyone buying a retail processor or complete machine this certainly isnâ€™t an issue. Where it is an issue is for some air coolers that hook on to the mount for security â€“ these will no longer work. More problematic is many advanced coolers and water coolers that require removal of the plastic mount and instead use the two holes on the motherboard. As there are now four holes, this can no longer happen as they are in a completely different position.
On the plus side, four holes make a lot more sense than two â€“ especially if you like to retro-fit your own water coolers. In fact, Socket A used four holes and this was a popular way to mount things.
So what else has changed with AM2? Well, very little really, aside from the fact that AM2 now houses everything from Sempron to FX processors. Initial memory speeds are 800MHz, but this will vary from processor to processor.
What is more interesting is what is going to be happening in the future. The current generation of processors are just a stop gap measure. As discussed during my visit to Semicon, 65nm is on its way. This will give rise to higher clock speeds and lower power consumption.
What is more interesting is the introduction of a shared Level 3 cache. The key word here is shared. Just adding extra cache would give minimal performance increase, but a shared cache would hugely impact multi-threaded performance. The affects of DDR2 latency would be dampened too. The obvious down side is more heat, lower yield and more cost. This will be the main reason that AMD has waited until 65nm.
What isnâ€™t known, is what processors will initially be rolled out with such cache. After all, server processors seem to be the first to get such a treatment and it may be a while before this technology trickles down to the rest of us.
Also mentioned by AMD was a compatibility with DDR3 and FBDIMMS. I can only speculate, but the document I read almost suggested that current chips already have this compatibility built in. This would suggest that only a motherboard upgrade would be necessary to support such a feature â€“ if and when necessary. Once again only time will tell and AMD has stated that it will be supporting DDR2 for at least two years, so anyone concerned about investing in a short-lived memory technology can rest assured.
Other improvements to look out for are increased HyperTransport bandwidth and the use of Co-Processsors using a HyperTransport Expansion slot.