PC100 CL=2 VS. PC133 CL=3 what's the difference?

[bupkus]

I'm ordering memory for an eMachine model eTower 700id.
Crucial suggests the part #CT217527, PC100, CL=2 but what if I order from Newegg instead? (See below) What's the difference for a celeron 700MHz?

Memory furnished with original purchase
Memory: RAM SD-64M PC100
MB: MB Anaheim-3 810 Rev. F
Motherboard furnished with original purchase

Newegg:
Crucial Micron 128MB 16X64 PC133 SDRAM 168Pins DIMM, OEM
CL=3-Unbuffered, Non-parity, 7.5ns, 3.3V, 6-Layers. Part# CT16M64S4D75.

 

[Lord Evermore]

Nothing since you're probably going to be using it at 100MHz, so the PC133 will be able to run at 100MHz CL2 in all likelihood. The Crucial recommendation is based on the maximum capabilities of your motherboard, which is a 100MHz bus, so it won't recommend PC133, even though PC133 CAN run at 100MHz, but may not in your machine. If your computer's CMOS setup doesn't give you an option for setting the memory speed manually, you may be better off getting PC100, as it may only allow reading the memory SPD, and it may not work since the memory will read PC133 not PC100.

 

[EdipisReks]

i've put pc133 in a celeron machine which had no memory settings in the bios. it ran just fine at 100 mHz.

 

[Lord Evermore]

That's why I said MAY. And just because a machine has a Celeron doesn't mean it's going to work the same as yours. Older proprietary boards often did not accept anything but a specific memory type (and new server boards still do). The board in the eMachine is apparently commonly used by many brands, but that still doesn't mean it will always work.

Of course, PC133 isn't all that expensive, so it's not a horrible thing if you get PC133 and it doesn't work. The board most likely will work with PC133, running at the fastest speed both the module and the board support, 100MHz.

bupkus: Incidentally, buying direct from Crucial is cheaper than Newegg. The module that you specified above is only 25 dollars at Crucial, 28 dollars at Newegg. Both have free shipping on it, but Crucial is usually much faster (2nd Day Air compared to FedEx Saver, and Crucial usually gets the part out the door within a couple of hours). The CL2 module of PC133 is also the same price of 25 dollars at Crucial, so there's no sense in getting CL3. The PC100 CL2 is actually more expensive at 28 dollars.

I didn't notice that Crucial uses different part numbers when you search using the memory selector and simply select a particular part from the list of types. Maybe only happens with certain modules, or it may be a sneaky way to make you think you're getting a "special" module that has to be used instead of the standard.

 

[bupkus]

Newegg was out of stock of their pc133 cl2 for $25 and I also get a free t-shirt. 🙂

 

[obeseotron]

PC133 is overkill, hell, PC100 ram isn't even necessary, the celeron 700 was a 66Mhz FSB chip. CL2 is faster than CL3, but you should be able to set either of those sticks to cas2 in your bios at 66Mhz.