A question about RAM configuration?

Question

I just replaced my 2 512MB sticks for a 2GB stick....would it hurt to put in the other two 512MB as well? I have heard they all need to match...is this true?

Answer 1

Here is the sad thing about RAM that many people do not know. RAM runs faster in your computer in pairs than it does individually. Buy buying two one gig pairs your front side bus speed would be faster. Buy using only one stick you have created sort of a bottle neck for information to pass through. Its a bummer to think that your 512 pair is faster huh? Anyway to answer your question my guess is it would work but once again your front side bus speed is limited to the speed of that single 2 gig stick.  

Now for the next issue that most people do not know, there is an issue with running any more RAM that 2 gigs in either Windows XP or Vista 32 bit. Ninety percent of the operating systems out the are 32 bit operating systems.  32 bit operating systems do not support more than 2 gigs and buying more RAM is a waste of money. I have herd rumors that some people are getting Vista to work with 4 gigs of RAM in 32 bit but not everyone. Lap top owners seem to be having the biggest problem with this. What is the way around this quagmire? Buy the Vista 64 bit operating system. The catch? You must have a 64 bit processor and if you do not know that then you must find out.

Edit update: Now that I know your two gig sick RAM speed of 677 then the fromula works like this. Two one gig pairs would have given you a fronts side bus of 800. Will you see the difference? Only if you are a gammer where speed matters.

Yes you can mix (sometimes) backwards compatable speeds.

Answer 2

Leave the sticks out. If you put them in you will slow your ram down to 533 as ram only runs as fast as the slowest ram. With XP unless you do a lot of multi-tasking, you will probably seldom, if ever, need over 2GBs of ram so you'd be running slower a majority if not all, of the time. Most apps, with a few exceptions are written not to use over 2GBs of ram:

http://dubiousquality.blogspot.com/2007/...

Answer 3

put em in and try em out! The older and slower RAM could cause a bottle neck of sorts, but may prove to be faster than running without them given that you're adding another gig of RAM and the speed differences aren't that huge. I'd also try adding them to the last two slots...not the second and third.

Answer 4

it should be fine, as long as your not doing hardcore benchmarking and high end program. you might only see bottleneck performance but no harm to your system.

post you whole system specs if possible.

Answer 5

Always install DIMMs with the same CAS latency. for optimum compatibility is is recommended that you obtain memory modules from the same vendor.

You can install varying memory sizes in Channel A and Channel B. The system maps the total size of the lower-sized channel for the dual-channel configuration. Any excess memory from the higher-sized channel is then mapped for single-channel operation.

A motherboard can usually handle up to three different different speeds, but all modules are reduced to the speed of the lowest module. So, keep that in mind.

If you install four 1 GB memory modules, the system may detect less than 3 GB of total memory because of address space allocation for other critical function. This limitation applied to XP and Vista 32 bit version operating systems since it does not support PAE (Physical Address Extention) mode.

Basically, this all means that it isn't a good idea to install the original modules unless they are from the same vendor as the new modules, but you can try and see if it will work. It can actually work for some time before an issue may arise. You could run your system for well over a year without any errors, or it could error out right away. If down the road your system enters a reboot loop, where it hits the Welcome Screen, shuts off, reboots, hits the Welcome Screen, shuts off, reboots, forever until you manually shut it off by holding in the power button, simply unplug your system and remove the "new" modules, close it back up, and boot up normally. You will be able to enter Safe Mode while it is in reboot loop error.

You can indeed put different sizes of RAM modules in a motherboard. What matters is that they match in Type, which means fsb, CAS latency, etc. It is a good idea to buy all from the same vendor, but you know now what to watch out for, and no lasting harm occurs after removing offending modules and booting normally. So, you really have nothing to lose in trying to make it work, and at the very least it may work long enough for you to purchase additional modules from the manufacturer you bought the 2 GB module from. I always install the full 4 GB in a 32 bit system even though I know the system will not see it all because it gives me the most optional RAM. By optional I simply mean the best chance for the most the system can see. It all depends on the hardware on the system. In Vista, the Video card RAM is better utilized, so if you use Vista operating system be sure to upgrade to a card with at least 512 MB of onboard memory. That means you would possibly have that additional 512 free that the video card would otherwise, "take" from the modules. It is all about Addressing Space. Physical memory is mapped to the Addressing Space, and as the upper forth GB is reserved for system uses in a 32 bit OS, if your hardware needs a full GB, then the fourth GB of physical memory cannot be mapped.

So, go for it, good luck and have a nice day.

Answer 6

Not totally, depend on your FSB speed, normally the original memory speed will be correct, the newer ones may be faster but are limit by your CPU's FSB speed, so adding the 2x512MB back in shouldnt harm it.

Answer 7

I have 2 slots in my pc, one has 1gig in, the other 512mb, computer recognizes  them both.

Answer 8

You can mix sizes not speeds.If all 4 sticks are the same speed you can use them all.

Answer 9

   I just put in a 1G and a 256MB In a 2005 Dell desktop Dimension 3000 and recognizinging it. as total 1280MB weather or not it is using it i don't know.