RAM Speed Question

[dbtmellis]

I decided to buy some RAM for my System. I have a Dell Insprion 530s, running Windows 7 64 bit

I do know that RAM has speed, listed in MHz, and Capacity, listed in MB/GB

So, my system has currently 2GB (2x1GB) of PC2-5300 modules installed, running at 667mhz

Crucial.com says my system can handle PC2-6400, which runs at 800mhz.

I ordered 2GB (2x1GB) of the PC2-6400.

I don't know if i should "add" these to the empty slots (i have four RAM Slots total) or should i "replace" these and run at 800mhz. I do believe that the system will run at the slowest mhz speed i have installed.

So...should i go 4GB at 667 or 2Gb at 800?

 

[nekkidtruth]

Replace. The system will default to running at the lowest speed.

 

[dbtmellis]

Thought so. Just wanted to see input from other users

I will probably buy the remaing 2GB of the PC2-6400 in a few months.

 

[nekkidtruth]

To be perfectly honest, I would keep the 4GB RAM in until you can get more of the PC2-6400 sticks. Although the 2GB RAM is faster, the 4GB is larger and will yield better overall performance. At least until you have more of the PC2-6400 RAM.

 

[whs]

Are you sure they are faster. Mhz is only part of the story - latency is another.

 

[dbtmellis]

how to check what the latency is?

 

[whs]

how to check what the latency is?

Look at the specifications - especially the first one (CAS). Because, if the Dimm is 20% faster in terms of Hz but needs 40% more cycles to execute, you have not won anything.

 

[dbtmellis]

Here is what i ordered

2GB kit (1GBx2), 240-pin DIMM, DDR2 PC2-6400 memory module
CT764974

• Module Size: 2GB kit (1GBx2)
• Package: 240-pin DIMM
• Feature: DDR2 PC2-6400
• Specs: DDR2 PC2-6400 • CL=6 • Unbuffered • NON-ECC • DDR2-800 • 1.8V • 128Meg x 64 •

This is what i have currenntly right now

1GB, 240-pin DIMM, DDR2 PC2-5300 memory module
CT700733

• Module Size: 1GB
• Package: 240-pin DIMM
• Feature: DDR2 PC2-5300
• Specs: DDR2 PC2-5300 • CL=5 • Unbuffered • NON-ECC • DDR2-667 • 1.8V • 128Meg x 64 •

According to Crucial, the CL (CAS) the lower the better.

So..my new RAM has a CL of 6, while my current RAM has 5.

 

[win7clutz]

Mhz versus Latency is almost irrelevant if you're not overclocking or trying you're luck as a bandwidth junkie...

Since your Dell bios doesn't provide tools to OC, as well as the MB was designed to run PC2-5300 not the 6400, there will be NO notable performance gain...

I'd suggest following the manufacturer specs with your upgrade to 4MB.

 

[whs]

Right.

 

[nekkidtruth]

Mhz versus Latency is almost irrelevant if you're not overclocking or trying you're luck as a bandwidth junkie...

Since your Dell bios doesn't provide tools to OC, as well as the MB was designed to run PC2-5300 not the 6400, there will be NO notable performance gain...

I'd suggest following the manufacturer specs with your upgrade to 4MB.

I agree. Unless you're overclocking it's not really a huge deal.

However, there will absolutely be a noticeable difference going from the 5300 to the 6400. Will it be epic? Most likely not but there will be a slight difference.

Right now though, don't mix and match the RAM. That generally causes way more issues than the gain. Stick to the 4GB's till you get the rest of the 6400's. When you've got those, throw them all in at once. Dropping down to 2GB of RAM regardless of speed is going to take away from your current performance.

 

[dbtmellis]

So...with the latency of my new RAM modules being 1 more than my current RAM, will i get any noticable change?

 

[dbtmellis]

I guess the concenus says that i should go with the 4GB at 667mhz.

I will still order the other two PC2-6400 probably in a few months.

 

[Wishmaster]

Motherboard itself plays a large role.

Some OEM boards will only run at a certain speed, and are locked to that speed.

Meaning it will only run at 667Mhz regardless if you put in 800/ 1066 or whatever.

But even if does, CL6 800 will not be much different from CL5 667. About the same.

In your case, quantity over speed will yield the best results overall IMHO

 

[whs]

I guess the concenus says that i should go with the 4GB at 667mhz.

I will still order the other two PC2-6400 probably in a few months.

That would be my vote.