OT: New computer - how important is the RAM speed?

bombaj wrote on 9/21/2004, 5:56 PM

Hi everyone,
I'll be buying some parts for a new computer soon and am a bit confused as to what RAM to get. Many people on these forums have said that what matters most is CPU speed, not RAM. So...should I stay away from these expensive "dual platinum triple latency" modules or will 2 regualr high speed modules from Kingston or Samsung do?

I'm considering a Pentium 4 3.0E GHz 1MB
SUS P4P800-E-DLX Intel 865PE, 800MHz FSB, Dual DDR400
Antec SLK3700BQE

Just not too sure about the RAM.

The computer is used for editing/photoshop and some web browsing.

Thanks!
bombaj

Comments

busterkeaton wrote on 9/21/2004, 6:10 PM

I would get the speed that is recommended for the motherboard. If you get very fast latency RAM, you can overclock your machine. If you are not going to overclock. You should buy good brand name ram, but you don't have to go for their most expensive model.

I know for example some of the latest Dell's would not work with lower latency RAM

Bill Ravens wrote on 9/21/2004, 7:44 PM

There are two things to consider when choosing RAM.The first thing is the rate at which the RAM chips communicate with the motherboard and the CPU. The more recent RAM chips communicate in a manner called Dual Data Rate (DDR) or a later variant, which is faster, called DDR2. The comm protocol is defined by the motherboard design, so, it is necessary to make sure you pick RAM that matches the mobo specification. RAM is named as PCxxxx, as in PC3000, PC3200, PC3500, PC4000, etc. The higher the number, the faster the comm data rate.

The second thing to consider is the latency spec, usually specced as something like 2-3-3-7. The latency is the time lag needed by the memory chip itself to access the proper address being asked for by the motherboard. The four numbers specify various aspects of this seek/retreive and answer tile lag. Obviously, the smaller the number, the better. If you see a term like CAS2, they are referring to the first number in the string. Typical DDR2, PC3500 RAM won't be better than 3-3-3-7, altho', there are some advertised to be a little faster.

The practical reality is that a great deal of speed advantage is wrapped up in the DDR rate, as specified by the PCxxx designation. It will pay you to get the right kind specced by your mobo. You don't need any higher data rate unless you plan to overclock. The benefits of getting low latency RAM is smaller, in nature, than the data rate. Current testing that compares DDR and DDR2 memory shows very small benefit to DDR2. This will change, however, as other motherboard designs evolve. In the bottom line, it's a question of what you want to pay for in memory. Higher and higher cost brings diminishing returns in overall speed.

bombaj wrote on 9/23/2004, 8:40 AM

Thanks guys for your answers.

I read that the P4 3.0C rev. is overclock friendly (3.6 gig + or - a few) so IF I did purchase that CPU, I would definatly buy faster than recommended RAM.

It seems there are 3 different versions of the P43.0 Gig CPU. The C, the E and now there is the new socket. Is there a performance diff between them? They cost about the same right now. Any advice?

Thanks...
bombaj

Bill Ravens wrote on 9/23/2004, 9:15 AM

The new socket design is in preparation for faster CPU's coming down the pike from Intel. It has no performance effect on the current P4 design. However, I will add that only the newest mobo chipsets from Intel come with this new socket design. So, what CPU you select is a function of the socket that your mobo selection comes with.

BillyBoy wrote on 9/23/2004, 10:52 AM

If you're going to overclock then do yourself a favor and read some reviews on sites for your particular motherboard. Just like we love to do video editing there are many gifted people devoted to squeezing the last ounce of performance out of a particualr setup.

Memory wise, most motherboards are rated much lower then they are capable of running. So if you're going to overclock it makes sense to use the highest speed memory you can. The people writing the reviews almost always say which brand and speed of memory they've used and how far they pushed things.

The catch 22 is while the raw horsepower of the CPU is the main factor, the bandwidth speed or how fast data moves between the CPU and RAM can add a big bounce. Faster memory allows a higher multipler. So everything else being equal using 3200 or 3700 memory over more bland memory will help IF your motherboard is stable bumping up the FSB speed. The review sites tell you how.