Which is the faster ram?

[jakobkraft]

My friend is trying to put together a PC for a graphic workstation, these are his choices, based on the mobo's that he has:

768 MB PC-800 RDRAM

or

1GB DDR SDRAM at 400MHz


Sorry if that's a stupid question, but he needs an answer fairly quickly....thanks!

 

[volrath]

DDR

 

[jakobkraft]

Originally posted by: volrath
DDR

That answers that...thanks

 

[homercles337]

They are both going to be just as fast as one another. The benefit is that DDR is cheaper and you will have that extra 256MB. However, how do you plan on running 768MB of rambus? These have to be installed in pairs. Are you running 2x128MB & 2x128MB?

 

[jakobkraft]

Originally posted by: homercles337
They are both going to be just as fast as one another. The benefit is that DDR is cheaper and you will have that extra 256MB. However, how do you plan on running 768MB of rambus? These have to be installed in pairs. Are you running 2x128MB & 2x128MB?

I?m not sure, he just said these were his options based on two mobos that he had ? maybe one of them has 2 128 sticks and 2 256 sticks...?

 

[Cerb]

Er, there's more than just that.
If it's a i850E vs 845D, 845E, or 845PE, you'd be better off with the RDRAM, as it will be faster, even at less than 1GB. If it's a 865 P, 875P, or their equivalent workstation/server chipsets, then DDR will be a faster option.

 

[batmanuel]

Originally posted by: homercles337
They are both going to be just as fast as one another. The benefit is that DDR is cheaper and you will have that extra 256MB. However, how do you plan on running 768MB of rambus? These have to be installed in pairs. Are you running 2x128MB & 2x128MB?

I think the DDR would be a bit faster in most benchmarks because of its lower latency, even though the maximum bandwidth is still the same. The difference depends upon what kind of PC3200 you have, though. If it can run 2-2-2 at 400MHz, it will certainly be faster. Running at 3-3-3, you won't see as big a difference. Running 2x128MB & 2x128MB could also make the situation worse for the RDRAM as well, since I believe the latencies get worse for RDRAM as you add pairs of memory, IIRC.

 

[CraigRT]

Originally posted by: Cerb
Er, there's more than just that.
If it's a i850E vs 845D, 845E, or 845PE, you'd be better off with the RDRAM, as it will be faster, even at less than 1GB. If it's a 865 P, 875P, or their equivalent workstation/server chipsets, then DDR will be a faster option.

I think he is right on this...
Just to clarify, I was confused by the first part. the 850 chipset is Rambus, and the other 3 845's are DDR.

 

[jakobkraft]

I just got more info:

the 1GB DDR SDRAM mobo has an 800 MHz FSB.

and

the 768 MB RDRAM mobo has 533MHz FSB.


So which is the faster option of those two?

(Remember price doesn't matter, he already pulled these off two dismantled machines, so he's not paying for anything...)

thanks..!

 

[Budman]

I would go for the 1 gb ddr dual channel with Hyperthreading.

 

[Cerb]

In that case, DDR.
The worst case for the 800MHz FSB one would be a 848P (single-channel but tweaked out), which isn't bad, and probably competitive with the RDRAM. However, there's a 90+% chance it is a 865P or 875P, which would definitely be superior.

 

[homercles337]

Originally posted by: Cerb
Er, there's more than just that.
If it's a i850E vs 845D, 845E, or 845PE, you'd be better off with the RDRAM, as it will be faster, even at less than 1GB. If it's a 865 P, 875P, or their equivalent workstation/server chipsets, then DDR will be a faster option.

Yea, exactly. Thanks for the added clarification about chipsets Cerb (edit: and the follow ups ). I knew i should have done that as soon as i hit the "reply" button.

 

[KamiXkaze]

yep just what everyone else has just said it.

IMO ddr all the way much cheaper than rdram

KxK