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Memory Question 2

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muthabored

Technical User
May 5, 2003
391
US
I'm looking to upgrade the RAM in a desktop that I just purchased. The RAM that's in the sockets is (2) sticks of 256 DDR 400 PC3200U - does the U mean it's UNBUFFERED? I've been searching for the differences between unbuffered & registered, as I don't want to purchase something that's incompatible with my system (HP Pavilion a818n). Thanks in advance!
 
Okay...so if the PC already has already has the 2 sticks of 256, do I have to buy 2 more sticks of 256 or can I do 2 sticks of 512 (so that I can have a 1 1/2 GB of RAM)?

Thanks for your reply!

 
A matched set of 512MB sticks should be fine as you won't be exceeding the board's maximum memory size of 4GB.
 
I am upgrading memory for a friend of mine who has a Dell Dimension (don't know which one) and I pulled the stik of mem in there which is one stick of 256... does this mean that it is not dual stick technology? I found the exact same make of memory that is currently in there now which is Hyundai, and from the old memory stick I saw that it is PC-133 memory. Thanks.
 
First mainstream boards using dual channel memory were DDR boards equipt with the Nvidia Nforce2 and Via KT890 chipsets and not older SDram types like the one you have.
So not likely to be a dual I'm afraid.
Martin

We like members to GIVE and not just TAKE.
Participate and help others.
 
Thanks Martin... I was pretty sure it wasn't dual stick but wanted to be sure. I need to get my friend up to a gig and didn't know if I needed to get two sticks of 512 or one stick of 1 Gig. So my next question would be, could I get away with two sticks of 512 for a board that does not embrace dual stick or would I need to just get one stick (1 Gig)?
 
Be careful with PC133. There may be a maximum size for a single stick that is lower on some newer computers. You need to go online with the model number at the manufactruers website and see what they recommend. is a pretty good site. Usually if you input the model and manufactruer of your computer they tell you what they recommend.

If you do not like my post feel free to point out your opinion or my errors.
 
OK, I need assistance... I pulled this memory out of a Dell Dimesion 1100R: Hynudai PC133U-3542HYM71V32635ATS-H-AA, 256MB, 133MHz SDRAM PC100 168 Pin
<b>I put in this memory: </b>
<b>Crucial says I need this memory:</b>

When I put in the memory, the MOBO beeped at me. When it beeped at me it was consistent short beeps. It would not boot up. I then took the other stick of memory (the original memory which was 256MB) and put it in along side the new memory (with the stick of 1GB nearest the processor) and it only recognizes the 256MB and not the stick of 1GB.

Can someone tell me where to go from here? Did I order the wrong memory and if so, should I order what crucial recommends? Do I need to do anything to the BIOS? I may just take it to someone if involves going into the BIOS because I don't want to mess anything up, as I am assuming I would have to "flash" the BIOS to update it right? I am not sure I want to risk doing that?....
 
I'm confused about your situation. The memory you said you bought is 512MB, not 1gb. Also, the Crucial recommendation you linked to doesn't make sense, because they're recommending DDR memory and your machine clearly uses PC133. Those memory types are physically different so that Crucial page must not be for your computer. If you order DDR memory it isn't even going to fit in the slot.

I tried looking up the Dimension 1100R but can't find it. The only machine I can find is the DDR based 1100 which you found at Crucial.

Your memory upgrade options depend mostly on the chipset on your computer's motherboard. It's likely your computer is limited to double-sided 256MB modules. Many P2 and P3 era machines have that limitation.

It's also possible your machine would work with 512MB modules, but the 512MB that you linked to isn't a very compatible one. Even though it appears to be double-sided, it actually requires your computer to utilize both sides of the RAM at the same time in order for it to work. This is a problem - many computers are unable to access more than 1 side of the memory at a time. The module you purchased appears to be a rather disreputable design. A good brand like Kingston or Crucial wouldn't build a module like that.

More detail:
In that description, it describes the chips as 64x4 high-density. That second number (x4) means that each memory chip only provides 4-bits each time it is accessed. The computer expects 64-bits at a time when it accesses the complete module. This means that it would have to use all 16 of the chips at once (16x4=64) in order to get the 64-bit output it is expecting. This is nonstandard. A properly built double-sided module should be able to fulfill the 64-bit requirement using only 8 of the chips at a time. If your 512MB module used "32x8" type memory chips (but still 16 of them total) instead of the "64x4" type, then it might work. This depends on whether your computer can handle 512MB modules though.

Note that you also see markings like "64x64". Those numbers with "x64" at the end of them are referring to something else - they don't tell you what kind of chips it uses.
 
dementg,
thank you for replying... i am confused as well. First of all you are right, it looks like the link i provided does in fact point to 512, but the mem we purchased had the same specs but was a gig. I was also really baffled by the crucial recommendation for the mem - as you can see the info i pulled off the existing mem does in fact point to PC133.

As far the not-so-reputable brand, that is the exact same brand in the PC currently, and to be honest, figured I couldn't go wrong with the same brand and pretty much exact same specs. However, given your post above,i may just contact Dell and have them give me a recommendation - there is no longer a warranty on the machine, and by the way, it is a P3 chipset. Unless you have another recommendation? Thanks again.
 
I can tell you right now that ALL Pentium III motherboards used PC100 or PC133 SDRAM. DDR SDRAM will not work. Plus, it is physically keyed differently like dementg mentioned. There are two notches in regular SDRAM and only one notch in DDR. So DDR shouldn't even fit to begin with.

Because the PC is pretty outdated, I wouldn't bother trying to find the right brand or quality. At this point, look on or eBay for a couple 128MB sticks. The max most PIII motherboards allowed was 1GB, though there are some that only went up to 512MB. Plus the biggest stick you can use in each slot will be either 128MB or 256MB on that motherboard. And if you have an older version of Windows such as 98 or ME, don't bother going over 512MB. It won't do you any good and could actually cause problems (see the FAQ section under my profile if you need an explanation).

Decent brands to go with: Micron (Crucial), Corsair, OCZ, Kingston, Samsung, etc.


Remember that it's not worth pumping much money into an upgrade. Every dollar over $50 is better used towards building a new one or even buying a new cheapie from Dell/HP/Gateway.

~cdogg
"Insanity: doing the same thing over and over again and expecting different results." - Albert Einstein
[tab][navy]For general rules and guidelines to get better answers, click here:[/navy] faq219-2884
 
Compatibility always gets trickier when you try to install the largest modules possible. The biggest allowed modules only work when they meet the specs exactly.

128MB modules should work easily. As long as the memory can handle PC133 you shouldn't have any trouble with those.

Double-sided 256MB modules (16 chips total) from a reputable brand should work on almost any P3. If it's single sided it might not work. If it's double sided but from a cheap brand, then it might have the nonstandard chip types on it.

512MB is the most risky. If it's a VIA VT82C694X (Apollo Pro 133A) chipset, then it might support single sided 256MB and double sided 512MB. That's the only P3 chipset I'm aware of that can use at least some 512s. I don't know of any P3 chipset that can use 1GB modules.

Normally I'd suggest ordering from Crucial, because they offer a compatibility guarantee. But they only give that guarantee if you order from the page that's written for your exact computer, and they don't seem to have yours listed. You might try calling Crucial and see if they can help you sort it out. Their prices are probably better than Dell's, but I might be wrong about that.
 
dementg and cdogg,
thanks for all your assistance - I ended up calling Dell and after much "service tag number" clarification he gave me the information to update the PC's memory. I wanted to be sure that I didn't overload the MOBO with too much memory and even if it is just an upgrade to 512 that is fine. Since Dell is proprietary anyway, I figured just getting the scoop from them would be better. I had a dell once and broke the RIMM slot on the MOBO trying to replace it (my first attempt ever to upgrade memory) and not only was it the wrong memory, but I had to build a new machine and THAT was an adventure to say the least. At any rate, thanks for all the help.
 
A star to dementg for the breakdown of how memory is accessed.
 
dementg,
you are never going to believe this - I called Dell. THey gave me the recommendation for mem, which was another stick of 256MB PC 133. They told me I would more than likely be safe with a crucial.com memory purchase. However, you were correct in your assessments: 1. It is correct that his chipset can only handle 512 as the max amount of mem. 2. I purchased the memory from crucial and when I got it was not double sided, it was single sided. The below error occured, once again, as you suspected it would.
The computer would not boot up, saying that there was a memory DECREASE instead of recognizing both of the sticks. We tried several different positionings of the memory sticks but to no avail.
Do you think the solution is indeed double-sided memory? What would you try before assuming the above? Thanks in advance.
 
cdogg said:
The max most PIII motherboards allowed was 1GB, though there are some that only went up to 512MB.

Yep, the 512MB limit doesn't come to much surprise as I mentioned earlier. Also you never said what version of Windows your friend is running. If it's Windows 9x/ME, then there's no point in maxing it out at 512MB. 256MB is the sweet spot for older versions of Windows, and I usually don't recommend going over 384MB.

With that said, double-sided PC133 is the most compatible across older motherboards. But the P-III motherboards (specifically the 810 and 815 chipsets) often worked fine with single-sided memory. It was the older Pentium II and AMD K6-2 motherboards that were picky about single and double sided.

So...

You said:
We tried several different positionings of the memory sticks but to no avail.

You said "sticks". What amounts are they? You already know the max is 512MB, and I thought the one you purchased was 1GB. It's just not going to work regardless of which slot you install it in. The largest amount you can probably use in each slot is 256MB, although I recommend you go back to Crucial and get two more sticks of 128MB PC133. This will take your total up to 512MB (cuz you still have the 256), perfect for an older system. Even just getting it up to 384MB is good enough, because the biggest bottleneck is going to be the old hard drive and outdated CPU - not the amount of memory.

~cdogg
"Insanity: doing the same thing over and over again and expecting different results." - Albert Einstein
[tab][navy]For general rules and guidelines to get better answers, click here:[/navy] faq219-2884
 
cdogg,
In my above post I mentioned that I called Dell and they told me that the max was 512. So I had purchased another stick of 256 to make a total of 512. The 1GB stick didn't work, thus calling dell and posting here, so I kind of already figured out that it wouldn't work.

Also the hard drive on the machine was replaced with a 160 gig (running great). The OS is XP which was also recently installed. The memory stick I got is not double-sided and I am guessing that is the issue, as it was mentioned as possibly being a problem earlier. If so, this may be the third time that I will be purchasing the "correct memory".
 
Airpan,
That's the info I was looking for. You never said you purchased a 256MB stick. You left that out when you said:

THey gave me the recommendation for mem, which was another stick of 256MB PC 133. They told me I would more than likely be safe with a crucial.com memory purchase.


Perhaps you misunderstood my last post. I knew in my first post (look at 28 Feb 07 13:08) that the 1GB stick wasn't going to work. I have owned and serviced many P-III systems from HP, Dell, Gateway, and custom builds. Many maxed out at 512MB, so as I said in my last post, that comes as no surprise.

I just wanted to point out that it probably doesn't matter at all about it being double-sided. Most P-III motherboards play well with either type.

Why do I feel like I'm restating my last post?
[wink]

~cdogg
"Insanity: doing the same thing over and over again and expecting different results." - Albert Einstein
[tab][navy]For general rules and guidelines to get better answers, click here:[/navy] faq219-2884
 
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