Sign in with
Sign up | Sign in
Your question

Mem Combination help!

Last response: in Memory
Share
January 29, 2004 10:54:34 AM

system A - KT266a with 1x 256mb DDR (266Mhz)
system B - KT400 with 1x 256Mb DDR (333Mhz)

plan to upgrade mem on both. either another 256 or 512.

1)Are there any limitations or combinations to be avoided?
2)can i use faster (333 or 400) memory in the second slot of system A? Are there any drawbacks?
3) Are there any drawbacks if all 3 slots are used?

Thank you for your help

More about : mem combination

a b } Memory
January 29, 2004 11:02:36 PM

You can use faster memory on the second slot of system A as long as the BIOS supports it. Here's what I'd do:

1. Pull the RAM from System B and put it in the second slot of System A (assuming modern BIOS is loaded).
2. Buy new RAM for system B.

<font color=blue>Only a place as big as the internet could be home to a hero as big as Crashman!</font color=blue>
<font color=red>Only a place as big as the internet could be home to an ego as large as Crashman's!</font color=red>
January 30, 2004 8:08:42 AM

Thank you for your reply.

So, if the bios supports it, there shouldn't be a reason not to use pc2700 or pc3200 on system A, right? Does it matter which slot it should occupy?

I guess i can do the same with system B, right? (use pc3200)

Ok, just 2 more questions:

1) What if system A's Bios doesn't support more than PC2100? Will it still accept a faster one and run it as PC2100?

2) Does it matter what size Mem i get or what slot it goes to?

Thank you for any help

PS: why are you suggesting i should buy a new one for system B and not for A instead? Is it only to check if it works before i buy?
Related resources
a b } Memory
January 30, 2004 2:49:07 PM

1) It should run the PC2700 as PC2100 in the second slot. I'd try the module from system B in it. Second slot, because it will look at the first slot first to determine appropriate speed.

2) All motherboards have some kind of limit for size they can support. Either of those should support 512MB, they probably support 1GB DIMMs but I'm not certain.

<font color=blue>Only a place as big as the internet could be home to a hero as big as Crashman!</font color=blue>
<font color=red>Only a place as big as the internet could be home to an ego as large as Crashman's!</font color=red>
February 2, 2004 10:27:55 AM

Thank you for your help.

There is still something that i'd like to ask, to simply clarify things in my mind but i kind of hesitate: i don't wish you to feel pushed or something. It concerns your response to the first issue: would there be a difference if the motherboard looked first at a pc2100 or a pc2700 at the first slot?

About the second issue: yes, i am aware about the size limit motherboards can support, that was not what i meant. My fault for being vague. What i really meant is combinations of chip sizes. Like, slot 1 has 256 pc2100, can/should the pc2700 in slot 2 be of any size (256/512/1G)?

Thank you for your patience.
a b } Memory
February 2, 2004 10:34:27 AM

You should always put the slowest module in the first slot just to make sure BIOS uses the SPD values from that module to set the speed of the entire memory bus.

Normally it's prefered to use the largest module in the first slot, but I've never had a problem putting smaller modules in the first slot, so that "rule" doesn't seem to mean much.

<font color=blue>Only a place as big as the internet could be home to a hero as big as Crashman!</font color=blue>
<font color=red>Only a place as big as the internet could be home to an ego as large as Crashman's!</font color=red>
February 4, 2004 9:21:51 AM

Thank you, you've been really helpful.

It seems that i should not have any concerns about memory chip combinations after all since i can use any size and faster chip in the other slots without compromises (given that they fall within the max mem limit supported by the motherboard).

Again, thank you very much.

Take care.
May 17, 2004 11:25:41 AM

Seems funny, after all this time, but here it is:

Recently i decided to get another mem chip for my KT266a(and after the advice i got above, i was going for pc2700 or pc3200, depending on price) and after talking to people from 3 different computer stores (all technicians) i got really really confused: they all said NOT to use anything faster than pc2100, for stability reasons. One was really adamant on that. Another said that for the KT266a it might depend on the motherboard (some work with faster mem modules, some don't) while the kt400 won't have a problem running pc2700 (slot1) and pc3200 (slot2) ...
Now, i don't know what to do... is it that they might not be THAT experienced...? (not highly unlike)...

Any opinions???
a b } Memory
May 17, 2004 10:26:53 PM

Hehe, I could tell you some storries about "technicians", but instead I'll just tell you this: As long as BIOS doesn't freak out when it sees the faster memory, it won't be a problem. You SHOULD set your memory for PC2100 speed, but it doesn't matter if that memory is PC2100, 2700, or 3200. In fact, PC2700 clocked down to PC2100 speed is more stable than PC2100. PC3200 clocked down to PC2100 speed is more stable still! You see, there is no minimum speed RAM can run at, only a maximum they tested it stable at. The slower the clock rate, the fewer errors you get. The higher quality the memory, the fewer errors you get. Faster memory has to be of higher quality in order to run faster, therefor it's more stable than the slower memory if both are used at the slower speed.

BTW, you know how many "technicians" have told me PC133 isn't backwards compatable to PC100 boards? They lied. I can honestly say they lied because they continued to repeat the myth even after they knew the truth. The deceived themselves (ie, lied to themselves) to justify their perceptions, and then repeated it to other people.

One problem occassionally comes up trying to run newer memory on older boards, which is density. That is to say, low density PC133 worked on nearly any board, while high density PC133 required newer chipsets. The same could be true of DDR memory as well, but I haven't encountered the problem with DDR motherboards yet.

<font color=blue>Only a place as big as the internet could be home to a hero as big as Crashman!</font color=blue>
<font color=red>Only a place as big as the internet could be home to an ego as large as Crashman's!</font color=red>
May 18, 2004 9:16:22 AM

Thank you for your reply Crash!
This ended up being a rather confusing matter...
So, you're saying once again that i shouldn't worry about it... I could try to see if i can borrow a faster than pc2100 chip from a friend, but is there a possibility of damage to the board or mem chip in case they proove incompatible? (although, you're saying i shouldn't worry about it)
If i manage to get it, do i simply insert it to the mem slot on the board? Is there anything else i need to do/set?

Thank you so much...
a b } Memory
May 18, 2004 9:40:00 AM

Nothing blows up, burns out, or anything like that. You simply plug it in, and it either works or doesn't. If faster memory doesn't work, it's because your BIOS sucks. Any faster memory can run at slower speed. DDR DIMMs for the PC follow a standard layout and use 2.5v-2.6v signals, there's no way to fry anything.

I've been doing this 7 years, I've looked into just about everything, tried most things, etc. I'm not like the typical technicians you talk to who work based on myths and legends, my knowledge is based on specifications, experimentation, and experience. I've never burned a memory module in my entire life, and I've worked with modules all the way from PC2100 to PC4000. In fact, I've used my PC4000 to test a board that was "made for PC2700". I've even ran it at speeds from PC1600 (DDR200) all the way up to PC4000 (DDR500) on the SAME BOARD, using an old P4S533 with P4 1.8A, and the CPU:RAM ratio set at 1:1 and 1:2. According to SiS the chipset can't even run PC3200 speed.

<font color=blue>Only a place as big as the internet could be home to a hero as big as Crashman!</font color=blue>
<font color=red>Only a place as big as the internet could be home to an ego as large as Crashman's!</font color=red>
May 18, 2004 11:16:03 AM

Thank you Crash!
And, yes, i know who you are, that's why i am here talking to you and asking help from you. Let me tell you i really appreciate what you do.

Thanks, man.
May 25, 2004 5:26:49 PM

This just reminds me that 'Technicians' are like auto mecanics. If you bring your system to them, and they think you're ignorant, they'll fleece you and whip out fancy terms to confuse you. It would be interesting if someone did an expose like they've done with auto mecanics (i.e. they unscrew a hose, take it in, and get told they need to replace the radiator). It'd be fun, set a jumper wrong, take it in, they tell you "you need a new motherboard" and BAM!!! out come the cameras. Granted, this does not describe all technicians by any means, but I've met some who use their limited knowledge of computers to try and feel superior. It's my experience that most people have some area of specialized, esoteric knowlege, so feeling superior about it is unwarranted. Granted, having computers as your special area of knowledge is a bit more handy than say, 18th century Russian Poetry, but still, not a reason to feel or act superior.

"The only way to overcome temptation is to yield to it" - Oscar Wilde
!