Can I go from a 2 slot memory to a 1 slot?

December 10, 2010 at 08:26:28
Specs: Windows XP
I have a Dell C521 and here is my system info:


System Manufacturer:Dell Inc
System Model: Dimension C521
System Version:
IdentifyingNumber: 94K50C1
System Type: X86-based PC


Mother Board Manufacturer: Dell Inc
Motherboard Model: 0UT226


Processor: AMD Athlon(tm) 64 Processor 3200+
Processor Manufacturer: AuthenticAMD
Processor Speed: 2004
Processor FSB: 1000


Bios: Dell Inc
Version: 1.0.3

************Memory Details**********

Memory Manufacturer:
Installed RAM: 962.56 MB
Maximum RAM: 16 GB
Total Slots: 4
Capacity: 512 MB,512 MB,
Memory Type: 0,0,
Speed: 533 MHz,533 MHz,
Slots: DIMM_2,DIMM_1,

I want to make this old dog improve on multitasking and speed. I went to and chatted with a rep that suggested I upgrade to this:

Now my question: if I order this do I remove my current 2 memory cards and install the new one in slot 1?

Any suggestions would be soooo helpful.....

See More: Can I go from a 2 slot memory to a 1 slot?

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December 10, 2010 at 09:00:18
Your motherboard supports dual channel memory. So ideally for best performance you should have identical capacity pairs of memory in both slots.

I had a quick look at the Dell online specifications for your model and it says the maximum memory is 4 GB though your post suggests 16 GB.

Your system supports:
Dual-Channel DDR2 SDRAM (533MHz)

Your system manual with regards to memory states:

Your computer has a minimum memory configuration of one DDR2 memory module. This memory module must be installed in DIMM1. If two or more DDR2 memory modules are installed, they should be installed in pairs of matched memory size, speed, and technology. If the DDR2 memory modules are not installed in matched pairs, the computer will continue to operate, but with a slight reduction in performance. See the label on the module to determine the module’s capacity.

Now to your question:
You currently have two sticks of 512 MB in each slot giving you 1 GB total dual channel RAM.

Your upgrade options are as follows:

2 x 1 GB RAM giving you 2 GB RAM in dual channel mode
2 x 2 GB RAM giving you 4 GB RAM in dual channel mode - This is your Max

What you are proposing is to put in 1 x 1GB memory in one slot. That will work. However, it will work in single channel mode and hence slower.

Furthermore when you want to upgrade later say to add another 1 x 1GB you may not be able to get a match to your original to create a matching pair. Some systems are not too fussy so long as both slots contain the same size and rated memory, others are more fussy. I do not know how yours will behave.

My view is go for a matched pair of 1 x 1GB. That way you get dual channel performance and it will be the better for it anyway.
Finally check your motherboard, does it have 2 slots or 4 slots? The manual suggests that it should have 4 slots.

If it does have 4 slots then your options increase.
For example you could add another 2 x 512 MB RAM in dual channel mode in the remaining two empty slots. This would give you a total of 2 GB (4 x 512 MB)

Personally in that event I would go for 2 x 1GB RAM in dual channel mode in the 2 empty slots. This would give you a total of 3 GB (2 x 1GB and 2 x 512 MB)

Hope it helps

When everything else fails, read the instructions.

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December 10, 2010 at 09:16:07
Yes, that helps tremendously....

"Personally in that event I would go for 2 x 1GB RAM in dual channel mode in the 2 empty slots."

Let me make sure I understand...

I need to purchase 2 1GB ram from the link I posted for on what what suggested by rep for a total of 3GB or I could purchase 2 2GB and go to 4. In removing the originals will I lose anything stored?

Is there another good site you would recommend to purchase ram?

And finally, will going to 3-4GB substantially increase the performance and speed?


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December 10, 2010 at 09:46:36
Assuming you're from the US, why are you buying from memorystock? Whenever you install multiple sticks of RAM, the entire bunch will always take on the characteristics of slowest stick. In other words, if you pair up DDR2-800 with your old DDR2-533, ALL the RAM will run as if it's DDR2-533.

According to Crucial, the Dimension C521 only accepts a max of 1GB per slot, for a total max of 4GB:

If it was my system, I would yank the old RAM, replace it with 4 x 1GB DDR2-800 & sell the old stuff for whatever I could get. Newegg has 2GB kits (2 x 1GB) for about $35. Too bad this A-Data is out of stock:

There are plenty of others to choose from though. Make sure whichever you get runs at 1.8v. And CAS 4 is faster than CAS 5:

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December 10, 2010 at 09:55:28
Most likely you are running a 32 Bit version of XP as opposed to 64 Bit version.
That being the case there is no significant advantage to going beyond a total RAM of 3 GB. Going beyond 3 GB is only worth it if you are running 64 Bit mode.
If you do go to 4GB then the upper 1GB will essentially be wasted.

You could read more on this here:

So go for an additional 2 x 1GB.
NOTE: It seems you can only have 1 GB per slot max. So the 2 x 2GB is NOT an option.

No you will not loose any data. RAM is volatile memory and all contents in RAM is unsecured and lost on shutdown. Your real data is stored and secured on your Hard Disk Drive

The site you have linked displays price in $.
I am UK based so I do not know what alternative vendors you can go to. Perhaps some US based readers might have a better idea on where you might get better value.

Newegg is a name that comes to mind:

When everything else fails, read the instructions.

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December 10, 2010 at 09:56:28
Just to add, DDR2-800 is the correct RAM to run with an Athlon 64 IF you want optimal performance. However, if all you want is better performance (not necessarily "optimal" performance) & money is a factor, just buy a 2GB kit (2 x 1GB), pair it up with your old RAM & let the bunch run as DDR2-533.

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December 10, 2010 at 10:25:03
Thanks to all!!!! You are AWESOME!!!!

Have learned a lot!

Think I'm going to opt for the 2 x 1GB 800 for now and yank the old ones, see how I like the speed and performance and if it's not enough order another set from the same company and bump this old dog to a 4GB....

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