SDRAM - is this PC133 or PC100?

[zeusfaber]

I've got a couple of SDRAM DIMMS, each bearing a sticker which says 512 MB PC133.

Each has 16 chips on, marked 5225405BTTAT PC100-222-6.

Would I be right in thinking the sticker is not being entirely honest?

A.

 

[wahnula]

Which sticker???

Download memtest86+ and CPU-Z, install one stick of RAM, then run the apps. These free apps will identify your RAM frequency.

Tony

Users helping Users...

 

[BadBigBen]

Would I be right in thinking the sticker is not being entirely honest?

why would you think that?



Ben

"If it works don't fix it! If it doesn't use a sledgehammer..."

 

[zeusfaber]

The DIMMs are new to me - and unfortunately the machine won't POST with either of them installed. This gives me a snag with testing them as recommended.

The stickers in question are printed paper labels stuck on the end of the DIMMs.

Why do I ask the question? Because I don't understand the way the specs work well enough. I thought PC133 chips were PC100 compliant, but not the other way round - and that the chips on the DIMM are PC100.

A.

 

[wahnula]

AFAIK, PC100 and PC133 are interchangeable, i.e. you can put PC100 in a PC133 PC, it just won't run at 133, it will run at 100. Likewise you can put PC133 in a PC100 PC, it will run at the slower frequency.

It's been a LONG time since I've dealt with either RAM, so take this info with a pound of salt. Here's a good discussion, but I can't vouch for its veracity:

http://www.computing.net/answers/hardware/pc100-vs-pc133/36897.html

I Googled "pc100 vs. pc133"

In any case, it should be cheap to replace the RAM, I have a drawer full of PC100 & PC133 sticks, I'm sure many others do too. I see it selling on eBay for $1-10 per stick. I might just put my collection up for sale!

Tony

Users helping Users...

 

[cdogg]

and unfortunately the machine won't POST with either of them installed

Quite a few PC100 and PC133 boards had limits on the size of the DIMM. For example, Intel's 810 chipset which supported the Pentium III was limited to 256MB per slot and 512MB total.

And if you haven't done so already, be sure to try the 512MB DIMM by itself in the first slot.


I think you could get away with a single 512MB DIMM on any Intel chipset that was newer than the 810, but definitely not on any that were older (that I know of). You also have pay attention to the "Mbit Support" rating of DIMMs which describes density and the layout of each chip on the DIMM.
Here's a chart that shows the chipsets' requirements:

http://www.intel.com/design/chipsets/mature/index.htm

~cdogg
"Insanity: doing the same thing over and over again and expecting different results." - Einstein
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[BadBigBen]

As mentioned beforehand, there are limitations that certain mainboards have...

I've seen mobos that only took single sided DIMMs and would balk with dual sided ones, like wise the module size...

and sorry about the question, as I reread the opening thread, it popped into sight, why you asked... (note to self >> carefully read, do not skim.. LOL)

it would be helpful to know what machine these are supposed to go into, and if the previous RAM modules worked or not...

Ben

"If it works don't fix it! If it doesn't use a sledgehammer..."

 

[wahnula]

Also...get the mainboard details and plug them into

http://www.crucial.com

's Memory Advisor tool. This SHOULD give you the correct RAM for you M/B.

Tony

Users helping Users...

 

[zeusfaber]

Gentlemen,

Thank you for some very useful advice and links.

State of play is this.....

The machine is elderly, currently working with a pair of 128 MB modules - and doing reasonably well in its intended role as a home fileserver. "There are those" who insist on using it as a desktop, and get upset by its palpable lack of oomph.

I can see now (thanks once again) that the machine already has all the memory it can take. This leaves me with a couple of sticks to return to the supplier.

In a way, this brings me back to my original question, but for a different reason now. If the sticks are genuinely PC133, I'll see how interested the supplier is in letting me return them. If they're only PC100, then they're "not as described", which gives me a bit more leverage.

Any thoughts?

A.

 

[wahnula]

Without a working machine to test them on, you are at the mercy of the seller. If s/he's a true eBayer, there will be a return allowed if you eat the original shipping and pay for the return shipping. I don't think you could determine the true RAM frequency without a working test machine or some expensive test equipment.

If the seller won't work with you, take a digital picture and resell them on eBay. As a guideline, I usually double the actual shipping cost to cover the eBay & PayPal fees.

Tony

Users helping Users...

 

[cdogg]

That's right. Unless you can get a PC to POST with the memory installed, you're not going to know which label is wrong.

I can tell you though after searching on the net, that part number (PC100-222-6) turns up a lot of hits on PC100 memory from Corsair and a few generic manufacturers. Chances are the PC133 label isn't right since it's not as specific.

~cdogg
"Insanity: doing the same thing over and over again and expecting different results." - Einstein
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