P4 and DDR

[ksoth]

The thing is Raystonn, you constantly stress that synthetic benchmarks make the playing field unfair, but you fail to explain the reason why in real world tests, RDRAM still failed. Look at some of Tom's benchmarks in

Quake III
i840 PC800 - 149 fps
440BX PC133 - 160 fps
i815E PC133 - 153 fps

Expendable
i840 PC800 - 101.8 fps
440BX PC133 - 105.7 fps
i815E PC133 - 102.8 fps

Unreal Tournamnet
i840 PC800 - 42.37 fps
440BX PC133 - 44.99 fps
i815E PC133 - 45.00 fps

In most synthetic benchmarks, yes, PC133 does trounce RDRAM. There were a few in the article where i840 did indeed beat PC133, but in most of these cases PC133 did beat i820. I mean, what's the deal with this? Here's the article I got the information from:

<A HREF="http://www.tomshardware.com/mainboard/00q2/000611/index.html" target="_new">http://www.tomshardware.com/mainboard/00q2/000611/index.html</A>

"We put the <i>fun</i> back into fundamentalist dogma!"

 

[Raystonn]

I just took a look at the benchmarks directly off the URL you gave. Most of the slight difference in scores seems to be more directly related to the chipset on the motherboard than the type of RAM being used. Take a look at the 440BX and the i815e for example. You see fluctuations in those scores that, in more tests than not, are greater than those between PC800 RDRAM and PC133 SDRAM. This tells me the largest factor in performance differences was the chipset. What was wrong with the i840 and i820 chipsets? What was wrong with the i815e that made is so much slower than the BX, with the same PC133 memory? I don't know, but none of these chipsets performed very well. I believe what we are seeing is some really crappy chipset designing back when they were rushing to get something new out. Does this say anything about the RAM being used in these platforms? Not in my opinion.

It would be nice to have a single chipset that supports both SDRAM and RDRAM so we can do a memory-only comparison. Until that happens though we are stuck benchmarking the RAM and chipset together. I will, however, say that the i815-i840 chipsets, coupled with RDRAM or PC133, performed really poorly.

-Raystonn

= The views stated herein are my personal views, and not necessarily the views of my employer. =

 

[ksoth]

I really don't buy your explaination of a crappy chipset. i840 is an extreme performance chipset for high end workstations. Intel, touting the benefits of RDRAM and trying to convince the world that it is the future of memory, would not waste time creating a crappy chipset. Most likely they did the best they could with what they had. It is believed by many in the computer world that Intel intentionally handicapped the i815 in order to make the RDRAM solutions look better. Via's chipset can't really be compared, well, because it's Via. Intel is much better at making chipsets than Via is. I just don't think Intel would make a crappy chipset for the "future" of memory technology.

Considering the huge differences in the technology behind SDRAM and RDRAM, it is extremely unlikely that we will see a chipset that supports both types. DDR and SDR SDRAM are more similar, so that is why ALi's MaciK1 and Intels Brookdale will be able to support both.

"We put the <i>fun</i> back into fundamentalist dogma!"

 

[Kelledin]

Actually, Anand looked into that in one of his reviews a while back. Whole detailed thing going that demonstrated that RDRAM actually <i>does</i> take less power and dissipate less heat than SDRAM. I don't believe he got a chance to compare it to DDR SDRAM though.

It's simply that the RDRAM acces patterns cause specific spots on a RIMM to heat up tremendously while the rest may just sit and chill. Overall the heat dissipation is less for the entire RIMM, but the extreme concentration at one spot creates the need for a "heat spreader."

I'll see if I can find the link to the review tonight. Or maybe Raystonn can dig it up...

Kelledin

bash-2.04$ kill -9 1
init: Just what do you think you're doing, Dave?

 

[Kelledin]

It would be nice to have a single chipset that supports both SDRAM and RDRAM so we can do a memory-only comparison.

That's what the i820 was supposed to be; we all know what a mess <i>that</i> turned out to be. Besides which, Intel blatantly and intentionally handicapped the SDRAM performance in order to push RDRAM. No disrespect to you or your job, but I wouldn't put it past Intel to try another such chipset and handicap DDR/SDRAM in some more subtle manner, just to keep pushing RAMBUS.

I think I'd have to see what someone like ServerWorks could do with the P4--see if they could produce both a DDR and an RDRAM chipset--and put the two head-to-head then.

Kelledin

bash-2.04$ kill -9 1
init: Just what do you think you're doing, Dave?