Ram incompatibility

[dakranii]

I have a Cognac Trigem mobo in an older HP with Celeron 800. Original came with 128 mb ram (1 stick) at pc100.

I bought a 128 SDRAM pc133 16x64 years ago that has always worked.

Just bought this from newegg http://www.newegg.com/app/ViewProductDesc.asp?description=20-141-205&depa=1 and it won't work.

Am I doomed to no more than 128's?

I put the 256 in slot 2 and it passed the bios screen recognizing the new amount of ram. Then when windows finished loading, it restarted...and continued this cycle. Booting, then restarting, etc. I put the 256 in slot 1 then and got nothing. It wouldn't even get past the ram count.

Here's a link to an Old thread about my board: http://www.e4allinc.info/dir1/motherboards/socket370/cognac_end_users.htm

They talk about the RAM needing to be double-sided. I didn't realize this would make a difference...would it?

sorry for the ignorance. thanks for any info you have.

 

[Osiris]

Well it depends. You might have two different manufactures of ram so that could cause a problem. The board might not support pc133. Usually if you have a board that has pc133 on it, you can go back to pc100, but not the other way around. In my situation, I had 512mb corsair pc3200 ddr400. Then I bought 1gb, 2 x512mb sticks, and when I installed them, it booted fine, the restarted, then restarted, then said:

Boot from cd
Boot from cd
Missing operating system

So I just left the ram installed, reformated and I was up and running again. So you might need to mess with it a little bit. Make sure it's inserted correctly too. With it not inserted all the way, it may boot and it may not, just depends on how much the contacts are touching at the time of boot. Heat moves thing even with nonmoving parts as with ram, so it can wiggle it's way out so to say. So see if this helps and let us know.

 

[dakranii]

Well, I had a 128 pc100 and added a 128 pc133 and have been running the two for a few years. It's the 256 pc133 that caused the problem. I tried every combination of 256 and 128, with both 128's and each stick in one slot then the other, solo and paired. No go. When I had the 256 seated in slot 1, though, with either 128 in slot 2, it counted ram at the bios screen and started windows, but never got beyond that...it just restarted the comp repeatedly. When the 256 was in slot 2, though, and either 128 was in slot 1, it never even counted ram at the bios screen.

I might just see if I can buy a double sided 256 stick and see what happens.

Anyone want to buy 2 256 pc133 SDRAM sticks?

 

[Osiris]

Just incase some one says you cant run the two together here 's this:

The PCxxx and CASx names are simply ratings of what the RAM is capable of running. For example, PC133 SDRAM is guaranteed by the manufacturer to run at 133MHz. This 133MHz is not a required operating speed; it merely indicates what the RAM is capable of. The same applies to the CAS rating.

RAM has no clock of itself. Its speed is entirely determined by the motherboard, and the settings in the BIOS. One DIMM is not capable of being "faster" than another DIMM if they are both operating at the same settings.

Because the PCxxx numbers are merely ratings, there are usually no problems mixing different RAM: PC100 SDRAM will operate perfectly fine together with PC133 SDRAM, using a 100MHz FSB. Remember you may try to run the PC100 SDRAM at 133MHz, but the manufacturer has only guaranteed it for operation at 100MHz. As usual, your mileage may vary.

Again, this applies to RAM of different CAS ratings. You can run CAS3 RAM together with CAS2 RAM, using the CAS3 setting in the BIOS. The CAS2 RAM will operate normally at CAS3. You may try to run the CAS3 RAM at CAS2, but as above, the manufacturer does not guarantee operation at this speed.

All SDRAM is backward compatible and can run at any bus speed slower than it is rated to run.

For example, a PC133 SDRAM DIMM is capable of running at 133MHz, 100MHz, and 66MHz. There are a few older
motherboards that require 66MHz SDRAM and that will not accept PC100 or PC133 SDRAM, but they are the exceptions to
the rule.

As part of the PC133 specification, PC133 RAM should be able to run at 100MHz, CAS2.

PC150 and PC166 are not official specifications, similarly with PC2400 (PC150 DDR) and PC2700 (PC166 DDR).

Looking at the speed ratings on the RAM chips themselves can give you a good idea of how high a speed the RAM can handle. The table below lists the nanosecond rating and the MHz speed rating.

 

[Osiris]

Did you try both pc133 together?

 

[dakranii]

Yeah, I did. I had 4 sticks. 1 - 128 pc100, 1 - 128 pc133 double-sided, and 2 - 256 pc133 single-sided. I tried every combination using both slots and all four sticks.

Like I said, it was weird that with the 256 stick in slot 1 I got a different result than with the 256 stick in slot 2. In slot one, it counted RAM at the bios screen and went on to boot windows. After booting windows it restarted the computer and continued this cycle until I stopped it. When it was in slot 2, it wouldn't even count the RAM at the bios screen. Just sat there showing me my HP logo, no matter which of the other 3 sticks I had in slot 1 (or none).

Does the single-sided / double-sided thing make a difference? On the post I gave above someone mentioned it had to be double-sided. I never imagined this would make a difference, but I will probably give it a try if eBay has anything for me.