PE 2550 MEMORY QUESTION

[ethanmcf]

Hello,

Iv been using a Dell PowerEdge 2550 for a while, it was shipped with 2GB of memory (512 x4) then after a while of usage I had the error message 'The amount of system memory may have changed' so I removed 2 of the 512 sticks and all seemed well, server was running on 1GB of memory. All of a sudden I had to do a reboot of the server to which I get the error message 'The amount of memory may have changed' I don't understand why, Iv tried to alternate sticks but to no success, even though system has 1GB installed the BIOS is reporting between 540MB and 556MB, this changes on every reboot and has only recently started happening again.

Any advice would be much appreciated.

Thanks.

[allen2]

Did you check your memory with somthing like Memtest ?

To diagnose fastly:

- put only one memory stick, if it can boot with only one if not put two. Then boot with the memtest iso and wait at least one pass (if the problem usually happen when the comp is hot but not from cold boot wait for at 3 passes).

- then try another stick or pair of stick ( if you're trying sticks by pair, you'll need to try all possible pairs if no error happens).

- If you get error with all sticks on the same ram slot, it could be a motherboard problem. So you might try (if the motherboard can boot) to put the memory in other slot.

Hope this helps.

[ethanmcf]

Did you check your memory with somthing like Memtest ?

To diagnose fastly:

- put only one memory stick, if it can boot with only one if not put two. Then boot with the memtest iso and wait at least one pass (if the problem usually happen when the comp is hot but not from cold boot wait for at 3 passes).

- then try another stick or pair of stick ( if you're trying sticks by pair, you'll need to try all possible pairs if no error happens).

- If you get error with all sticks on the same ram slot, it could be a motherboard problem. So you might try (if the motherboard can boot) to put the memory in other slot.

Hope this helps.

Thanks for the reply, I will try the memory test, yea the Server requires two sticks at a time, which have to be pairs.

I Will post back when i've done the test, and report back my results,

Again, Thanks

[Ponch]

I've seen such problem on a Dell server solved by Bios upgrade.

[ethanmcf]

I've seen such problem on a Dell server solved by Bios upgrade.

How would that work though, because i believe you need to load the new bios with a floppy disc, and i only have a floppy disc drive on the server, nothing else.

[Ponch]

1) I'm not sure at all this will fix your problem.

2) Dell has Bios upgrades that run under Windows or even a BartPE/WinPE.

[ethanmcf]

1) I'm not sure at all this will fix your problem.

2) Dell has Bios upgrades that run under Windows or even a BartPE/WinPE.

Just Done a memtest, and im getting failures every other second, so i'm assuming its the memory thats faulty. But it costs more me to replace the memory that what the server is worth, waste of a server really!

[Tripredacus]

1) I'm not sure at all this will fix your problem.

2) Dell has Bios upgrades that run under Windows or even a BartPE/WinPE.

Just Done a memtest, and im getting failures every other second, so i'm assuming its the memory thats faulty. But it costs more me to replace the memory that what the server is worth, waste of a server really!

Hmmm... let me put things together... memory needs to be in pairs... replacement memory costs more than the system... this sounds like my old computer! Which used first-gen RAMBUS where 2x1GB sticks cost about $700 last I checked! Its a little cheaper now I think as time goes on but I have already moved on away from that (except I still have that system) now my main PC uses DDR2.

[ethanmcf]

1) I'm not sure at all this will fix your problem.

2) Dell has Bios upgrades that run under Windows or even a BartPE/WinPE.

Just Done a memtest, and im getting failures every other second, so i'm assuming its the memory thats faulty. But it costs more me to replace the memory that what the server is worth, waste of a server really!

Hmmm... let me put things together... memory needs to be in pairs... replacement memory costs more than the system... this sounds like my old computer! Which used first-gen RAMBUS where 2x1GB sticks cost about $700 last I checked! Its a little cheaper now I think as time goes on but I have already moved on away from that (except I still have that system) now my main PC uses DDR2.

Yea the server uses 4x512Mb sticks, requires them in pairs, The stick reads: PC133R-333-542-82

http://cgi.ebay.co.uk/Dell-Poweredge-2550-Memory-RAM-512MB-PC133R-SDRAM_W0QQitemZ300356084581QQcmdZViewItemQQptZUK_Computing_Networking_SM?hash=item45ee9e2365#ht_1638wt_964

Bare in mind the server set me back £30, so the memory will work out as more.

Just don't understand how it can run faultless for months on end, then all of a sudden, decide to stop.

It also has a 128Mb Base memory i think its called, installed, which i next to the RAM Modules, don't understand what that is for either.

[Tripredacus]

The base memory may be there if the board supports RAID at all, not sure. I'm surprised about this 133MHz RDRAM thing, it appears that there are a version of RDRAM designed to work on the 133MHz FSB! They should still actually be the faster components instead, such as my PC has 2x 256MB and 2x 128MB but they are PC800 and run on the 400MHz FSB with Intel P4 CPU, which we know wasn't really 400MHz anyways.

One thing to keep an eye on tho, is that the older RDRAM has a different pin-package (and price) than the newer, more common stuff. For example, if you just search for RDRAM you will most often find 184-pin package offerings. However the board I have does not use this kind, it uses 168-pin instead. As an example for me, in order to keep matching sets of Kingston or Samsung, I would use this option:

http://www.google.com/products?q=rdram+168-pin+samsung&hl=en&aq=f

The idea I could use 2x1GB sticks and 2 blanks, however these options do not exist at least right now! Also the idea of using 4x 512MB might be there, those prices are significantly lower, however most options are USED products with no warranty.

If you are getting memory that is said to work with your particular system, make sure to check if Dell ever did a revision, and also that the RDRAM you are getting has the correct number of pins that you need. It would be a waste if you bought it and it was the wrong ones. I wanted to find an example of the 1GB RDRAM with 168-pin but it looks like neither google shopping nor pricewatch actually have them listed.

[ethanmcf]

Yea the server offers RAID, so that clears that one up,

it is 168 pin memory.

I live in the UK, so the postage on those items is steep.

Shame you cant use normal SDRAM, because i've got loads of it laying around!

ive just looked inside the machine im using to type this up on, and it takes 2x256Mb, 168Pin SDRAM memory.

isit worth sticking them in the server? or do i run the risk of ruining the sticks/motherboard?

[Tripredacus]

Let me put it this way. I have found the hard way that RDRAM was not matched in speed until DDR2 came out. To say DDR2 @ 533 is the same as RDRAM @800 as far as what I can see. I notice a different between DDR (not DDR2) speeds vs RDRAM speeds. Not so much DDR2. For me, its not "too bad" you can't use SDRAM, the timing and speeds should be noticeable for you. Do not think it would be good to go to SDRAM because it will be slower and you may end up noticing it. I am glad I did not stay with DDR for too long!

[CoffeeFiend]

You are making me curious with all this RDRAM talk. I don't see how it's even related to his server, I figured I must be missing something.

About the RAM costing more, well, old computers are like that. Older parts cost more, and the computer ain't worth a whole lot either being so old (P3 era). It's a good part of why I don't stick with older stuff, it always ends up costing more than it should (doubly so for servers). Pretty much everything this old box can do, can easily be done with a virtual machine.

Dell PowerEdge 2550 Technical Specifications, for those who might want to peek. It lists RAM as being plain old ECC registered PC133 SDRAM.

[ethanmcf]

You are making me curious with all this RDRAM talk. I don't see how it's even related to his server, I figured I must be missing something.

About the RAM costing more, well, old computers are like that. Older parts cost more, and the computer ain't worth a whole lot either being so old (P3 era). It's a good part of why I don't stick with older stuff, it always ends up costing more than it should (doubly so for servers). Pretty much everything this old box can do, can easily be done with a virtual machine.

Dell PowerEdge 2550 Technical Specifications, for those who might want to peek. It lists RAM as being plain old ECC registered PC133 SDRAM.

Yea, its purely used as a DC, DNS and DHCP, nothing more, but its a waste of a machine, when everything in it works perfect bar the memory, so can I just use normal SDRAM in the machine? Sorry I'm more of a software person as a posed to hardware.

[Tripredacus]

Yeah, the only reason I thought it was RDRAM was because it needed to be in pairs. Prior to Dual-Channel technology, RDRAM was the only type to my knowledge that had such a requirement. The fact that there is 168pin SDRAM PC133 AND 168pin RDRAM PC800 (for use on 133MHz FSB) adds to the confusion. However, we can easily do a comparison now as to what memory you actually need.

This page has a picture of RDRAM 168pin:

http://www.amazon.com/EDGE-memory-168-pin-RDRAM-103996-B21-PE/dp/B0000A58OS

Main things to notice is the location of the notches (or the keying) of the edge (no pun intended) connector. These are in a different place than the memory from the ebay auction. Also, (again to my knowledge) all RDRAM has heat spreaders on them, because of the speed they run at. Only premium SDRAM came with heat spreaders.

You should be able to compare the pictures to the memory in your computer to see where the notches are, and which type you actually have.