New RAM along with old RAM?

G

Gordon.C

Member
Hi,

I am about to get new 8GB RAM stick clocked at 1333GHz and I was wondering if I could simply pop in the new stick among my old RAM in the computer.

The old RAM is 3 x 1GB sticks clocked at 1066GHz.

Is it a problem to combine those? Obviously I am not going to need 11GB of RAM (in the following 10 years at least) but I rather have all my RAM employed if possible than have it lie in my drawer.
 
you technically can, but it is not the best idea. The best thing would be to get a 2x4GB kit and replace one of your 1GB sticks. This will cause you to run in Dual channel mode making more or less double the bandwith you would have with the 1x8GB add in.
 
This more depends on application.

I take it you have a 64-bit operating system? If not then 8GB of RAM is a waste of money. But if you do:

Back when I had my old P4 DDR400 setup, I found that more RAM in single channel was more beneficial than running dual channel. The reason being, back then it was comparing 2x1GB versus 2.75GB with 4 sticks (256MB and 512MB with the 2 1GB modules). Obviously, it does not matter how fast your RAM is if you do not have enough and the system has to resort to using page file as memory, which is why at this time more RAM was better.

But today, I dont think anything over 4GB is not needed right now. I only got 12GB because RAM is so cheap now for whatever reason, theres no reason not to. But unless you are running programs that are 64-bit and really eat up resources like video or photo editing then I would just go with dual channel as suggested. But it sounds like you are saying you have 1 8GB stick and 3 1GB sticks? Im not sure you can run dual channel with that 8GB module involved without having a second one.

But remember, if you use the old RAM then all your RAM modules including the 8GB one will be clocked at 1066MHz since that is the slowest one.
 
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Need to know limits of mb so whats the model #?
Also whether or not the processor and operating system is 64 bit to see if its compatible/usable.
 
Benny Boy said:
Need to know limits of mb so whats the model #?
Also whether or not the processor and operating system is 64 bit to see if its compatible/usable.
Click to expand...

My MoBo supports up to 24GB of ram and I indeed am running a 64bit system.

I was only curious whether it is possible to combine several different types of RAM.
 
Gordon.C said:
My MoBo supports up to 24GB of ram and I indeed am running a 64bit system.

I was only curious whether it is possible to combine several different types of RAM.
Click to expand...

This is what will limit you:

1. What the motherboard supports (DDR, SDR, DDR2, DDR3 etc) and size supported.
2. Module timings
3. For dual channel, size and timing are all that need to match along with type (DDR, SDR, DDR2 etc)

As long as you meet those you can use whatever you want.
 
Size does not need to match, neither does timing.

All that needs to match is the memory type, which as a motherboard will only support one standard of memory at a time, and with only very few supporting more than one anyway, that really isn't a problem.

If size is different, it will either only utilise an amount equal to the smallest module for each DIMM, for example if you have a 1GB DIMM and a 2GB DIMM, 1GB will be used for each, resulting in 2GB total memory in dual channel.

You can also have flex mode where the amount mentioned above is put in dual channel, and any additional memory is put in single channel. Using the example above, you would still have the 2GB total, but the 1GB remaining of the 2GB DIMM would be utilised in single channel only.

If timings or frequency are different, it will be underclocked to the lowest value. If you have a 1333MHz and a 1600MHz DIMM, both will run at 1333MHz always, unless overclocked of course.

The main issue is mismatched memory. Memory sold in a set is matched and provided it has correctly passed quality control, will work. If you buy more than one DIMM or more than one set separately, even if the same model from the same manufacturer, they may not be matched so may not work properly together.

Put simply, in theory, throw whatever mix of the same standard of memory that you want together and it will work, in practice, you don't know until you try.
 
Aastii said:
Size does not need to match, neither does timing.

All that needs to match is the memory type, which as a motherboard will only support one standard of memory at a time, and with only very few supporting more than one anyway, that really isn't a problem.

If size is different, it will either only utilise an amount equal to the smallest module for each DIMM, for example if you have a 1GB DIMM and a 2GB DIMM, 1GB will be used for each, resulting in 2GB total memory in dual channel.

You can also have flex mode where the amount mentioned above is put in dual channel, and any additional memory is put in single channel. Using the example above, you would still have the 2GB total, but the 1GB remaining of the 2GB DIMM would be utilised in single channel only.

If timings or frequency are different, it will be underclocked to the lowest value. If you have a 1333MHz and a 1600MHz DIMM, both will run at 1333MHz always, unless overclocked of course.

The main issue is mismatched memory. Memory sold in a set is matched and provided it has correctly passed quality control, will work. If you buy more than one DIMM or more than one set separately, even if the same model from the same manufacturer, they may not be matched so may not work properly together.

Put simply, in theory, throw whatever mix of the same standard of memory that you want together and it will work, in practice, you don't know until you try.
Click to expand...


Im not sure if they have changed anything in the past few years, but you couldnt run dual channel with different module sizes with DDR.

And what you stated doesnt make sense. Your saying that half the stick will be running in dual channel mode while the other half is in single channel? Impossible.
 
G80FTW said:
Im not sure if they have changed anything in the past few years, but you couldnt run dual channel with different module sizes with DDR.

And what you stated doesnt make sense. Your saying that half the stick will be running in dual channel mode while the other half is in single channel? Impossible.
Click to expand...

No, not impossible, you not having heard of it and it being impossible are two different things.

You have 2 sticks of memory: 1 x 1GB and 1 x 2GB

With flex mode, you will have 2 x 1GB run in dual channel, so have the extra bandwidth. The additional 1GB capacity, that would otherwise be redundant, is running in single channel to allow for all of the capacity to be used.

So:

A size equal to the storage capacity of the smallest DIMM will be used from each module in that channel, if it is 512MB, 512MB will be used from each DIMM, if 1GB, 1GB will be used, etc. Any additional, unused memory from DIMMs with a larger capacity than the smallest will be used in single channel mode.

Without flex mode you would have two options:

1. All DIMMs run in single channel
2. DIMMs use a capacity equal only to the smallest module, leaving the rest unused.

With flex mode, all storage is used AND you have the performance that is gained from running memory in dual channel.

http://www.intel.com/support/motherboards/desktop/sb/cs-011965.htm

=EDIT=

oh and you can always have used modules with different densities, even at DDR and DDR2, provided they are in single channel
 
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Aastii said:
No, not impossible, you not having heard of it and it being impossible are two different things.

You have 2 sticks of memory: 1 x 1GB and 1 x 2GB

With flex mode, you will have 2 x 1GB run in dual channel, so have the extra bandwidth. The additional 1GB capacity, that would otherwise be redundant, is running in single channel to allow for all of the capacity to be used.

So:

A size equal to the storage capacity of the smallest DIMM will be used from each module in that channel, if it is 512MB, 512MB will be used from each DIMM, if 1GB, 1GB will be used, etc. Any additional, unused memory from DIMMs with a larger capacity than the smallest will be used in single channel mode.

Without flex mode you would have two options:

1. All DIMMs run in single channel
2. DIMMs use a capacity equal only to the smallest module, leaving the rest unused.

With flex mode, all storage is used AND you have the performance that is gained from running memory in dual channel.

http://www.intel.com/support/motherboards/desktop/sb/cs-011965.htm

=EDIT=

oh and you can always have used modules with different densities, even at DDR and DDR2, provided they are in single channel
Click to expand...

Iv never heard of that. And Iv never had a DDR motherboard that supported it either.
 
So I got a new 8GB RAM stick. This was not for the discussed computer but for my Mac Mini and I gotta tell you the difference was quite unexpected.

Before I had only 2GB RAM which comes in the cheapest available Mac at the moment. It used to be quite slow because if you used more than 3 applications at once you ran out of memory pretty fast. At some instances you could even run out of memory when browsing quickly through youtube.

Well so I popped in a new 8GB stick and left one 1GB from the old set and the difference is amazing. It cost about $50 and now I can finally use Mac the way it is supposed to be used - I never have to close any apps, I tried to fire up 25 apps at once and still had about 1.5 GB free ram. Even when you bootup and start application for the first time there is an improvement in speed.

Bootup had slight improvement in terms of time and shutdown literally takes place in less than 4 seconds.

So the lesson here is, if you are looking to buy a Mac and dont want to spend fortune. Get the cheapest Mac Mini and add to it an 8GB RAM it will cost you about $700 and you will have a decent Mac experience
 
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