RIMM's 800 vs. 600

[YZ12569]

I was looking at some Dell systems on the web and they said they offer both 800 and 600 MHz RIMMs however I have done some very limited research on RAMBUS' website and found no trace of a 600 MHz chip.

So question 1... If I went with this since it obviously does exsist, would I take a huge performance hit.
And 2... well I guess there is no 2 but here is a link to a chart I was looking at that shows nothing slower than 800.

Thanks,

 

[fkloster]

I don't believe PC-600 works on any Dell 8100 systems. I thought for sure that PC-600 doesn't work on i850.

 

[dullard]

Yes, Dell still tries to sell the slow PC600 Rimms. This question has been asked here before, and no one could come up with much good data to compare the performance of the two (the one benchmark I saw showed the PC800 with a slight lead, but that was on a much slower computer, 1.4 GHz I think). But since the price difference is negligible, why go with the slower memory?

 

[YZ12569]

It was offered as an option on this system: OptiPlex GX400 MiniTower

 

[NelsonMuntz]

I would say the performance hit would be pretty hefty in memory intensive applications. PC800 RDRAM has a memory bandwidth of 3200 MB/s (which is exactly what the P4 has) and PC600 RDRAM only offers 2400 MB/s. That's a 25% difference and could make a huge difference when memory matters. I would definitely suggest that you pay the extra $$$ and get the PC800 RDRAM.

 

[YZ12569]

30 bucks off is a big difference when buying 100 computers

 

[YZ12569]

Thanks Nelson... I appriciate the input very much!

 

[Athlon4all]

PC600 is supported by 850. It though performs very poorly. It should be stayed away from, only go with PC800.

 

[dullard]

Ahh you are comparing these:
128 MB total PC600 RDRAM (base price)
128 MB total PC800 RDRAM ($0 more)
256 MB total PC600 RDRAM ($149 more)
256 MB total PC800 RDRAM ($179 more)

Here is my thoughts, buy your 100 computers with 128 MB PC800 RDRAM. Then go to pricewatch and purchase 200 RIMMS of 64 MB PC800 RDRAM at $16 a piece. That is you get 256 MB of PC800 for $32 more than the base price. That should save you ($179-$32)*100=$14,700 from Dell's excessive memory prices.

I did the same, but I got 1 GB of memory and saved $400 on 1 machine.

Edit: for the $179 you pay at Dell you could buy 512 MB of memory at any other location (currently that is $160 at pricewatch). Thus you'd have a total of 640 MB in each machine for less money!

 

[Noriaki]

Actually "PC600" should be PC533...it only runs at a 266Mhz DDR clock, not 300Mhz...not sure why they call it PC600...it actually has the same peak bandwidth (in single channel) as PC133 SDRAM, or in Dual channel as DDR266 (PC2100).

And it works in the i820 and i840 boards (Pentium3) and I think that if you are buying P3s, SDRAM is probably a better choice. SDRAM is better suited to that CPU. In this platform PC800 gets beaten by SDRAM in some cases (hence the i820 being "replaced" by the i815), PC600 certainly would. But again it's sort of moot..if you are buying a P3 it's a waste to buy Rambus. The P3 can't use the bandwidth anyways.

For the i850 were RDRAM really gets to stretch it's legs and show off, PC600 isn't supported anyways.

I wouldn't bother with PC600 at all...it seems kind of like buying PC66 SDRAM...

 

[dullard]

<< I would say the performance hit would be pretty hefty in memory intensive applications. PC800 RDRAM has a memory bandwidth of 3200 MB/s (which is exactly what the P4 has) and PC600 RDRAM only offers 2400 MB/s. That's a 25% difference and could make a huge difference when memory matters. I would definitely suggest that you pay the extra $$$ and get the PC800 RDRAM. >>



I don't think current P4 chips fully utilize 3200 MB/s. Even with dual Xeon's I doubt I use my full bandwidth. PC800 is overkill for slower P4's, so in reality you won't see a full 25% speed difference in your programs. But as the P4 ramps up past 2.0 GHz, you bet the PC800 will definately be needed.

 

[YZ12569]

Dullard I do believe that is what I will do, I was considering it and now that you have done the math for me that looks best.

Thanks all