Questions about RAM

[Qyot27]

A forewarning: I'm dealing with outdated RAM types here (PC133 SDRAM, not DDR-anything), and am not interested in buying a whole new computer just because of this minor issue. This setup works fine as it is, I just put a new graphics card in it in fact, but there are some very small issues with lag in a couple places and I hope maxing out the RAM will solve or greatly alleviate the problem.

So I want to upgrade my RAM. Currently, this computer has one stick of 256MB PC133 SDRAM, and the chipset specs state that it can handle a total of 512MBs. I'm looking for either another stick of 256MB RAM to add to what I've got, or a 512MB stick to replace the one that's in there entirely (unless of course the spec sheet on Intel's website for the i810e is wrong and I can actually have 768MBs of RAM in this thing - still, a 256MB stick is probably cheaper).

A couple years ago, however, I'd tried putting a stick of 128MB SDRAM in this computer and couldn't (or more hopefully, just thought I couldn't, which would make me feel like an idiot but at least more comfortable with doing this now) because the stick was too physically large to fit (which is where the 'or so I thought' part comes in; maybe I just didn't realize how to put the darn thing in, but I'm fairly sure it actually was larger than the clamps allowed for).

Anyway, with that in mind, I want to know a few things:

*Are all desktop SDRAM sticks 168-pin?
*Are said SDRAM sticks physically the same size as DDR266? (I ask because I had ordered a stick of 512MB DDR266 to put in here only to find out this doesn't take DDR memory; the DDR stick and what I've got are the same physical size, though)
*Does Non-ECC or ECC matter in terms of size, or performance, etc.? I suppose this question also applies for DDR variants, whenever I do finally have a setup that needs DDR.

Finally, and perhaps most importantly in terms of the order itself, has anyone ever used memorystock.com? I found an entry for the computer make I have, and it lists having compatible memory modules available, but I've never ordered from them before.

For reference, this is the relevant page:
http://www.memorystock.com/orderitem.as ... dlId=29786

[BasharOfTheAges]

SDRAM as an overreaching category includes both what you have and the various Double Data Rate (DDR) standards above it. Your PC133 SDRAM runs single word transfers at a clock speed of 133MHz. They're generally all 168-pin, but they're certainly not interchangeable (though you can sometimes have backwards support of about 1 clock step within a family). ECC is used for parity error checking, mostly in servers. It's costly, and not really used that much in the home market.

All that said, you're probably going to pay a premium over what it's worth for an 11 year old technology.

[Qyot27]

SDRAM as an overreaching category includes both what you have and the various Double Data Rate (DDR) standards above it. Your PC133 SDRAM runs single word transfers at a clock speed of 133MHz. They're generally all 168-pin, but they're certainly not interchangeable (though you can sometimes have backwards support of about 1 clock step within a family). ECC is used for parity error checking, mostly in servers. It's costly, and not really used that much in the home market.

All that said, you're probably going to pay a premium over what it's worth for an 11 year old technology.

Well, I don't really consider $20-25 a premium; maybe in price-per-megabyte, but when comparing it to the normative price for sticks of (justifiably, much higher capacity) DDR2 or DDR3 that are on Newegg or Amazon, it's still pretty cheap. And yes, I know DDR is also a form of SDRAM, I just wanted to make it clear I didn't mean DDR at all.

When you say "They're generally all 168-pin, but they're certainly not interchangeable (though you can sometimes have backwards support of about 1 clock step within a family)", what exactly do you mean? The clock speed of the RAM vs. the front side bus, or something else? My FSB is currently set at 100MHz rather than 133MHz, but the RAM is PC133.

[LantisEscudo]

PC133 SDRAM, PC100 SDRAM, and PC66 SDRAM were all available in 168-pin DIMMs, and were by spec "compatible" with other sticks and motherboards rated for the previous generation (i.e. using PC133 RAM in a PC100 motherboard or vice versa). In practice, bad things happen if you tried to mix speeds or tried to put slower sticks in a motherboard rated for a faster speed.

DDR266 RAM is 184-pin DIMMs, so no, they are not physically compatible.

[Kionon]

I have some PC133 SDRAM 256MB sticks lying around, I think. What I need is the far more costly 512MBs to bring my G4 tower to 2GBs of ram.

[Qyot27]

Well, I ordered the right 256MB stick and installed it after it arrived this morning. The only problem is that Windows wants to spazz out if I try to use both it and my existing 256 MB stick at the same time (using the new stick on its own Windows doesn't have a problem with) - I get the 'your BIOS is not fully ACPI compliant' warning, and can't even log into Safe mode.

The kicker, though, is that this computer is set up as a dual-boot, and the Ubuntu side doesn't have any problems seeing and displaying the total from both sticks, nor did Memtest86+ find anything wrong. It's just Windows. Maybe this is the opportunity I need to take to do a reinstall using the copy of XP Pro I bought a year and a half ago instead of the XP Home restore disc that came with this thing. If it comes to trying to upgrade the BIOS to get Windows to play nice, I have no clue where to start looking.

[kmv]

http://forums.pcper.com/showthread.php?t=417158

[Qyot27]

http://forums.pcper.com/showthread.php?t=417158

I disabled the Parallel, Serial, Game, and Midi Ports (because they were all enabled), turned ACPI off, the error persists - actually, with ACPI turned off, Windows just reboots endlessly. There is no APM option in my BIOS. I told it to Reset Configuration, to Reset to Setup Defaults, still nothing. Legacy USB was already disabled. I disabled the Floppy Drive and the Floppy Controller, again nothing. The boot order was already set to CD-ROM first, Hard Drive second. I've been running SP3 since I had to restore Windows the last time (back last May).

The only two plausible things I can come up with are:
1) Windows can only handle 256MBs if I've got my ethernet card, USB 2.0 card, and graphics card in there. And there's no way I can settle on losing any of those. But this is completely dependent on point number 2, because like I said, Ubuntu 9.10 has no problem at all detecting the cards and seeing/using all the RAM at the same time (I even ran x264 with --preset placebo to test - sure enough, the RAM usage went over 300MBs, and probably would have gone higher if I'd let it).

2) It's entirely an OS problem I need to solve by doing a fresh install of Windows XP Pro from the SP3-slipstreamed disc I created over a year ago, instead of relying on the restore disc that came with this thing which is XP Home and that has no service packs applied to it (which I immediately go about installing after the system finishes coming back).

[Qyot27]

Well, it turns out I did have to upgrade the BIOS, because the version I had really wasn't capable of remaining ACPI compliant if there was 512MB in here. Luckily I found a site that had the upgrade I needed, I flashed the BIOS, and now Windows boots up fine and detects/displays all 512MBs in my System properties.

Trying to find any degree of information on exactly what model and version I needed and actually had it to download was like trying to pull teeth, though.