DDR SDRAM chipset for PIII

[Guest]

Both ALi and VIA are going to release a DDR SDRAM chipset for PIII, but I really doubt that PIII can make good use of the bandwidth since it's FSB is just 100/133mhz SDR (unlike Athlon which has a sychronized FSB of 100/133mhz DDR). If this is the case, wouldn't it be rather pointless to have a DDR platform for PIII?? Or will PIII work with a DDR FSB?

 

[rcf84]

alot of companys will make ddr for the p3

1. Nividia
2. ATI
3. VIA
4. micron
5. Ali

the p3 fbs is a true 133MHz

the Athlon and the p3 dont have a real 200 or 400MHz bus

its really 2 X 100mhz and 4 x 100 thats all it is

 

[mpjesse]

I'm thinking the DDR chipsets from VIA and Intel will probably not support P3's. I'm thinking they will be designed around the P4.

But, the P3 would make use of DDR memory because it really doesn't require anything specific. DDR RAM uses it's power on the rise and fall of a cycle, requiring only a special chipset- not CPU. DDR RAM is really 100mhz and 133mhz RAM anyways. And like the last dude said, P3's have a true 133mhz bus.

-MP Jesse

<P ID="edit"><FONT SIZE=-1><EM>Edited by mpjesse on 11/29/00 01:16 PM.</EM></FONT></P>

 

[Guest]

"DDR RAM uses it's power on the rise and fall of a cycle, requiring only a special chipset- not CPU. "
Yes I know damn sure it will WORK, but is it taking FULL advantage of DDR SDRAM's bandwidth? If I remember correctly, i840 with it's dual channel RDRAM doesn't really give PIII anything much other than reduced latency because the FSB is limited to 133Mhz. It's when P4 came out with QDR FSB do we get to see the wide bandwidth coming into play. Therefore, I think not only the chipset but also the CPU has to support a particular data rate or bus speed (in this case either 133Mhz x 2 or a real 266mhz FSB) to get the most out of the RAM's bandwidth otherwise it's just the RAM and the chipset that's talking in 133Mhz DDR but between the chipset and the CPU it's still 133Mhz SDR.

Or may be Intel would release a new version of PIII supporting "double pumped" 133Mhz FSB?
doubt it

 

[Lucol]

Not taking into account overhead from the AGP graphics board, and UDMA hard drive and any other peripherals attached to the bus, in theory, it would be pointless to enable a PIII with DDR SDRAM, since the PIII can only transfer data at a maximum of 1.06Gb/s between itself and RAM. But since it's not the only component communicating with RAM at the same time, I would have to say that enabling DDR on a PIII should reap some benefit, how much, who knows.

 

[Guest]

i have yet to see a superior chipset from either company.

 

[Grizely1]

I doubt they will "Double pump" it because that would require work on the chip itself, and they don't want to bother with that.

 

[Guest]

I'll say DDR SDRAM would give PIII about 2~7% boost at most.

Definitely not worth the money.

 

[Guest]

cas 2 memory means it sends information every two clock cycles of the actual memory clock speed.
so ddr memories should be cas 1 memory in a way as every second clock cycle is every cycle of the bus.
this means double the performance of the memory so the benifits are as good as the athlons

Smart people aren't smart they just view things in a different perspective

 

[Guest]

the memories large bursts will still be the same but the short bursts will be up to double the speed, like 64KB bursts.

 

[Guest]

What? CAS 1 DDR SDRAM?? I thought all DDR SDRAM to date are CAS 2.5?

I'm sorry ,but I have absolutely no idea about the burst data thing (in fact, whatever you mentioned doesn't quite make sense to me), but since PIII DDR SDRAM motherboards should be reviewed by Tom fairly soon ,I suppose, we'll see about if it really does give PIII a final bit of performance boost.