AMD Rev E: Unofficial Support for DDR500

[FarFarAway]

It seems that AMD have put a backup plan into place to support DDR2. :

Potentially as a backup plan, the Rev E chips include unofficial support for memory faster than DDR400, without overclocking the Hyper Transport bus.

So here's really what AnandTech are on about:

Prior to the Rev E CPUs, the Athlon 64’s memory controller supported enough dividers to allow for DDR400 to be supported at all clock speeds; from 1.8GHz all the way up to the present-peak of 2.8GHz on the Athlon 64 FX-57. The Rev E CPUs support those same dividers, but add the following:

13/12, 7/6, 5/4 and 4/3

So it ends up like this (Source: AnandTech):



So this is good for what?

With the move to dual core however, the effective memory bandwidth that each core gets is significantly reduced, as they both have to share the same 128-bit wide memory interface normally dedicated to a single processor. So in theory, the new dual core X2 line of processors could be a good candidate for these new memory dividers.

The other situation where higher clocked memory is important is with higher clock speed CPUs. The faster that your CPU clock gets, the quicker it can process data and thus, the faster that it needs information and the more memory bandwidth that it needs.

So there you go - memory seems to be playing a bigger part in the X2 series of CPU's

Well it seems like this higher bandwidth does not produce much more benefit to us

Based on the tests that we’ve seen here today, AMD’s reluctance to move to higher bandwidth DDR2 offerings makes a lot more sense. The plain fact of the matter is that at the current clock speeds at which the Athlon 64 and X2 line are running, most desktop applications see virtually no benefit from higher bandwidth memory. It is possible that server usage models may show a greater performance boost, but it is highly unlikely for a mission critical server to be equipped with anything that isn’t an officially supported standard - especially memory.

And last words:

Down the road, as CPU speeds and the sheer number of cores goes up, then higher bandwidth memories will definitely make much more sense. But for now, for the majority of the population, these new memory dividers won’t do much for you.

The performance improvements themselves aren’t tangible, but if you are trying to squeeze every last ounce of performance out of your system, then these new memory dividers offer you one more avenue to do so. If you have memory that can run at higher than DDR400 speeds without any reduction in latency, then by all means, explore the new dividers; just don’t expect them to change your life.

Well now the decision to not go to DDR2 makes more sense to me as it doesn't produce much more perfromance.

Maybe DDR3 will do?

We'll see

Here's the full article with benchies and stuff AnandTech

 

[JN]

Nice find kemp

Shame you just missed the weekly newsletter with this one

 

[bloodthirst]

ddr2 is a waste of time i think they should just wait for the arrival of ddr3

 

[enVias]

ddr2 is a waste of time i think they should just wait for the arrival of ddr3

DDR2 isn't a waste of time..

 

[NickS]

I also thinnk they should go right to DDR3. DDRII is just...not good.

 

[Dav0s]

its better than ddr1 nick. but it is way before its time atm. however with the inrtroduction if dual core it wil come into its own. (all outlind in the article if you care to read it)

 

[FragTek]

DDR2 is in fact better than DDR1. It's the lack of large performance gain to cost ratio and support that has made DDR2 a stinker.

I feel that AMD should continue on course as planned and sit out the DDR2 revolution and wait for DDR3 to come onto the playing field.

 

[bloodthirst]

sit out the DDR2 revolution and wait for DDR3 to come onto the playing field.

exactly.... how long actually is it before the release of ddr 3 anyway?