PC100 vs PC133 SDRAM

[ojai00]

Hey guys. My co-worker was just telling me how PC133 SDRAM is actually slower than PC100 SDRAM because of a timing issue, and that was the reason why PC133 RAM cost less than PC100 RAM when it first came out. Can anyone verify this and tell me the current status, as in any fixes for it. Thanks in advance for any input.

 

[josphII]

that is total BS
pc133>pc100
133=more bandwidth than 100
i gain 4fps in q3 when running pc133, as opposed to pc100

 

[ojai00]

Yea, that's what I thought too. He told me that everyone bought PC133 because they thought that since PC133 is an upgrade from PC100, it would be faster. Thanks for your input josphII. Anyone else?

 

[etalns]

I use to run pc100 on an old comp, then I popped in pc133. It made a little differnece on my benchmarks, I went from 512 pc100, to 512 pc133. One thing you might wanna remember though, is that this benchmark did not test your RAM too much, it was mainly video card/cpu.

 

[Kingofcomputer]

Assume it's PC133 cas3 vs PC100 cas2.
cas3 is really slower than cas2, needed 1 more clock cycle for the initial data burst, after that no difference, but PC133 is 7.5ns, PC100 is 8ns, 1 additional clock cycle delay is just 7.5ns, that's almost nothing. At 133Mhz, the memory bandwidth gains 33MHz than running at 100Mhz, that should override the additional cas latency.
Athlon or Duron 100Mhz fsb on VIA KT chipset, Sandra shows higher memory score for running the memory at PC133 cas3 than PC100 cas2.

Also, any good PC133 cas3 memory is able to run at PC100 cas2.

 

[ojai00]

Ahh...now that clarifies everything. Kingofcomputer proved his standing...once again. Thanks dude. Now how can I check what kind of RAM I have. When I was buying RAM (generic...sad) I remember asking the guy which RAM I should get, but I don't remember which one I actually did get.

 

[Kingofcomputer]

Sandra - it can tell the spd info, good manufacturers put the part number into it, so you can find out what module you have, but not the exact chip. it also reports the timing of the memory running at.

Ctspd - it only tells the spd info, good for quick check. it tells the cas latency, ras-to-cas delay, ras percharge at 66, 100, 133Mhz, spd version, dimm manufacturer, dimm part number, etc.

Look at the module - good manufacturers put a sticker on it with the part number. for example, genuine Micron made module has a sticker with logo and part number, Crucial module is the exact genuine Micron made module with an additional sticker with Crucial logo and Crucial part number.

Look at the chips - this is the only way to find out what exact chips are on a module. ram chip manufacturers have decoder or datasheet for you to check on their websites. this is the only way to find out the real speed of the chips on a module.

 

[ojai00]

Nice. Thanks. Happy Holidays to all that read this...