Have there been any comparisons? rdram/ddr?

I was parusing a magazine when I noticed that some 845 P4 boards are comming out with ddr support.
Does ddr come close to rambus's thruput?
Have there been any conclusions as to which is better?
I noticed that VIA is making a ddr chipset for the P4...any thoughts on this one?
What say you Ed? Skip?Joe?anybody?

Tom's Hardware has been covering this pretty well. They started out trying to totally debunk Rambus, and have seemed to come around to admitting there is some merit to rambus' claims. However, from what I gather, DDR is far more cost effective, and Rdram has failed to give the gains in throughput that were expected...Plus, latency is a problem.

This is a link to an interesting, albeit older article about rambus...


http://www6.tomshardware.com/column/00q3/000719/

RAMBUS vs DDR
is like SCSI vs IDE

In both cases, the fisrt one, cost alot more.
And in some case offers better preformance over the compitition.
So When buying one of the More $$$ options you have to ask yourself is the extra $$$ I am spending worth teh extra preformance?

SCSI is 500% the price of IDE for at max 50% the preformance.
True RAMBUS is not that much more than DDR, but its the same idea

Thanks guys, I was just wunderin if the ddr with a P4 would be a waste of money, and you pretty much answered my question.
Too bad Intel didn't come up with a ddr solution for the P4 before the competition (VIA) did.
Intel seems to be slow to catch on to what the public at large wants these days.
Thanks again,
Doc

I was reading the front page of [H]ardocp this morning and it sounds like they are going to publish a big P4 motherboard roundup in a couple of days comparing various ddr and rdram boards and chipsets. Maybe that will give some more insight on what the various ddr chipset solutions are going to perform like compared to rdram.

Here's the link.........

http://www.tech-report.com/reviews/2001q4/p4-chipsets/index.x?pg=1

Haven't had a chance to read it all the way through. If anyone else has, any impressions?

Well, it looks like the same story as the past few articles I've seen; RAMBUS is fast, but it's not the fastest memory technology out there (despite what many believe). The most efficiently designed chipsets tend to win the day, not the memory that can trick SANDRA into thinking it's the greatest thing in the world. Read the benchies - the RAMBUS board is usually being beaten by something, whether the P4X266 or SiS 645 or i845D, it's definitely not close to a clear overall winner.

RAMBUS was introduced to the computing scene not by Intel's concern for the public's interest, but by RAMBUS's incentive plan with Intel. Tests like these (which have been repeated by several other sites) show that RAMBUS, even with the P4's heavy reliance on its FSB bandwidth, offers very little, if any, gain despite a heavier price tag than DDR.

Heres the picture i see:

i850-100%
SiS645-99%
P4X266A-98%
P4X266-96%
i845D-94%
i845-66%

Here is another link, this one at Anandtech

in many other post i have discussed my opinions on both RAMBUS and DDR

neither one really impress me

DDR = sdram doubled pipelined

RDRAM = Multiplexed bus system

what makes RDRAM what it is the the dual channel

i do think the RDRAM is the fastest, but cost is expensive

i can't wait for the next RAMBUS chipset, using pc1200 (533mhz)

that way i can overclock my 850 chipset alot more.

my RDRAM is currently holding me back. its maxed out

when we see holographic memory, then i will be impressed

Here the theorical stats

Dual Channel PC800 RDRAM
Clock 400 Mhz
Differential? Yes 2x
Bus Width in Bit 2 x 16-bit = 32-bit
Bus Width in Byte 2 x 2 byte = 4 byte
Peak Bandwidth 3200 MB/s

PC2700 DDR-SDRAM (DDR333)
Clock 166 MHz
Differential? Yes 2x
Bus Width in Bit 64-bit
Bus Width in Byte 8 byte
Peak Bandwidth 2666 MB/s (25% jump from PC2100)

PC2100 DDR-SDRAM (DDR266)
Clock 133 MHz
Differential? Yes 2x
Bus Width in Bit 64-bit
Bus Width in Byte 8 byte
Peak Bandwidth 2133 MB/s

PC1600 DDR-SDRAM (DDR200)
Clock 100 MHz
Differential? Yes 2x
Bus Width in Bit 64-bit
Bus Width in Byte 8 byte
Peak Bandwidth 1600 MB/s

PC133 SDRAM
Clock 133 MHz
Differential? No 1x
Bus Width in Bit 64-bit
Bus Width in Byte 8 byte
Peak Bandwidth 1066 MB/s

PC100 SDRAM
Clock 100 MHz
Differential? No 1x
Bus Width in Bit 64-bit
Bus Width in Byte 8 byte
Peak Bandwidth 800 MB/s

tomshardware did review the SIS645 chipset with the new DDR333 and it show almost the same result on benchmark than the RDRAM, so i dont think for the tiny difference its worth buying RDRIMM modules, at that rate it proly spread more heat and cost alot more since big company must pay an extra fee to RAMBUS corp. for using his technology. Crucial, among others big seller, are pretty tired to follow Intel's partner so i wont bet too much about the RDRAM lifetime since DDR is cheaper, they tend to sell more.