Memory Question For Intel

[WhiteKnight77]

I am looking at getting my Ma an Intel Pentium 4 2.8 Northwood 2.8GHz 512KB L2 Cache Socket 478 68.4W Single-Core Processor - OEM that has a 533mHz FSB. While I am pretty confident about getting the right memory for an Athlon XP (easy as pie really), I am not sure for Intel. What speed of DDR RAM do I need to use the chip to the fullest at the proper FSB? Do I need PC 266 or PC 333?

Thanks.

[ROCO*AFZ*]

I am looking at getting my Ma an Intel Pentium 4 2.8 Northwood 2.8GHz 512KB L2 Cache Socket 478 68.4W Single-Core Processor - OEM that has a 533mHz FSB. While I am pretty confident about getting the right memory for an Athlon XP (easy as pie really), I am not sure for Intel. What speed of DDR RAM do I need to use the chip to the fullest at the proper FSB? Do I need PC 266 or PC 333?

Thanks.

Need to know what mainboard you have. If you get the model, go to www.kingston.com

Follow the memory configuration. It is by mainboard or brand model. It will tell you how much that board can take and what options there are. Then take that part # and plug it into pricegrabber.com.

Very easy for any mainboard.

if you don't want to open it, try cpu-z (google it) it should tell you what mainboard you have.

[WhiteKnight77]

Her MSI 651M motherboard can handle up to a 533mHz FSB (and why I chose the chip I did), but I just went to Kingston and it gives me the chioces I already asked about. It doesn't tell me which will allow it to run at 533.

[CR6]

I believe Intel Northwoods (I own two: a 2.5GHz @400MHz FSB and 3.4GHz @800MHz FSB) maxed out at dual-channel DDR400 = 800MHz FSB

So I'm not sure if you mean your mobo supports total 533FSB (i.e. dual channel DDR266) or total 1066FSB (i.e. dual channel DDR533)

I would suggest you download the Intel CPU identifier program and it will tell you the FSB of your CPU.

http://downloadcenter.intel.com/Product_Fi...41&lang=eng

[WhiteKnight77]

I will be buying the chip and the memory at the same time. I want to run it at 533. MSI 651M-L is the motherboard she has with a Celeron already on it. I want to upgrade it to the Northwood listed above and get the right RAM to go with it at the same time.

[CR6]

I will be buying the chip and the memory at the same time. I want to run it at 533. MSI 651M-L is the motherboard she has with a Celeron already on it. I want to upgrade it to the Northwood listed above and get the right RAM to go with it at the same time.

A ha, I see what you mean now. I checked this page and it appears that your mom's SiS chipset does NOT support Dual Channel

http://www.asisupport.com/p4_chipset_info.htm

So ... basically what that means is that even though your P4 2.8 CPU could run at 533FSB, you will never be able to run the CPU at its full potential as the max FSB you can run it at is limited to 333MHz because your motherboard's chipset that only supports up to 333MHz FSB as below:

Chipset

• SIS® 651 Chipset

- High performance host interface 400/533MHz

- Support 64-bit high performance DDR333/DDR266/DDR200 memory controller

If I were you, I'd get DDR266 memory if possible, as it runs at half the FSB speed of the CPU. There is a chance that the mix of timings would be kinda funny mixing a 533FSB CPU with DDR333, but I'm just guessing.

That, and the fact if your mom's using the computer, she won't be able to tell any appreciable diff between DDR266 vs DDR333 performance.

[ROCO*AFZ*]

Ahh i misunderstood the question. 266mhz ram is what you want. DDR does 2 per clock cycle so 266x2 = 533

800mhz fsb takes ddr 400. 400x2 = 800

It throws you because they say 533 ram sometime when it really only runs at 266, just does double in each cycle over ddr1.

[WhiteKnight77]

OK thanks guys. Now I can find some for her to help get some more speed from her PC (and my Pops too).

[CR6]

Ahh i misunderstood the question. 266mhz ram is what you want. DDR does 2 per clock cycle so 266x2 = 533

Actually, that SiS mobo doesn't do dual-channel. So the P4 will be "supported" at 533FSB, but in actuality the real FSB will be 266MHz.

That was the case with most early P4s. Even though they could run at 400FSB with Rambus RDRAM, only DDR266/333 was available early on for the majority of folks who used DDR RAM with the Intel 845D motherboards.

So in the end, when upgrading old systems, you have to be pretty careful and do your homework (e.g. if the voltage of your RAM doesn't work with the motherboard etc). Hopefully where-ever you buy stuff will take returns.

Personally, I find Crucial is a good place to get legacy RAM, and you can use their tool to find out which of their RAM is right for your mobo

http://www.crucial.com/store/listparts.asp...%20%28651M-L%29

Interestingly, they guarantee their DDR400 RAM will work with the mobo.