Types of RAM

marka87uk

I thought I was pretty tech-savvy but just looking at the different types of RAM is confusing me!

http://www.scan.co.uk/Products/ProductInfo.asp?WebProductID=121514
- This is really cheap - 1GB DDR2/PC4200 RAM.

http://www.scan.co.uk/Products/ProductInfo.asp?WebProductID=232551
- This is better looking, more expensive 1GB DDR400/PC3200 RAM.

Which one is better? I guess the more expensive one even though it's 'PC' rating is less?

What RAM would you suggest is the best 1GB performance vs price RAM on this page -
http://www.scan.co.uk/Products/Products.ASP?CatID=22&Category=Memory&Thumbnails=yes

?

Not looking to spend much more than £100 - and obviously the cheaper the better - but I don't want something which would provide poor performance!

davels

Hi

Which motherboard do you have...? If you know that, I can find out what memory it can support... you should (sometimes must) use the same memory as you already have onboard...

A nice & easy way to find out is to visit the memory configurator which is at http://www.crucial.com/uk/... that'll lead you to a suggestion of which memory will work in your machine! And it's probably cheaper than Scan!

-davels-

marka87uk

Cheers for that, I don't have a motherboard yet - planning a new system - but I'm most probably going to get the Asus A8N SLi Deluxe.

It's recommending me PC3200, so I guess I'll go for that.

moneysavingme_2

Always go for the one the motherboard recommends, also check the asus website for a list of compatible memory as some of the asus boards can be very picky.

Toxteth_OGrady

The reason it's recommending PC3200 is because the frontside bus (FSB) speed of the mobo is 800 MHz. That's the speed at which the CPU communicates with the RAM. So the RAM data rate that matches the FSB is 400MHz double data rate (DDR). If you multiply the RAM speed by 8 it gives you the advertised rating, i.e. PC3200.

Until the very recent arrival of 1000 MHz FSB mobos, the highest you would ever get from an online memory checker would have be PC3200, because that's the highest manufacturers' rating. However PC4000, PC4300 and PC4400 have been around for a while. Why?

It's to allow you the overclock the FSB to get better performance out of your CPU and RAM.

If for example you have a 2.8 GHz CPU, with DDR400 (PC3200) RAM the FSB is running at stock speed of 800MHz. The CPU and RAM achieve this by running at stock voltages.

You can however overclock in the BIOS by setting a higher FSB frequency. The speed of your RAM will appear in the BIOS at its single data rate of 200. However you can set this in 1Mhz increments. So if you set 250 you are setting a FSB speed of 1000 MHz, your RAM would be overclocked to the equivalent of DDR500 and your 2.8 CPU would be operating at 3.5 GHz.

The ability to do this is massively enhanced by the quality (read - price) of the RAM you buy. When I had Kingston HyperX PC3200 RAM with a 2.8 P4, I could overclock the RAM to 228 MHz.

WARNING Overclocking is risky -even if you know what you are doing. You can (a) invalidate your warranty and (b) very quickly burn-out and kill your CPU, mobo and RAM.

When you overclock you create lots of additional heat, even more so if you increase the CPU voltage and RAM voltage. So advanced cooling is required. Extreme overclockers use water cooling. You also affect the stability of your system. There is a limit to which the components will overclock and run stable. The art is to find that limit - the lower quality the RAM the lower that limit is likely to be.

At the moment I have a 2.8GHz P4 overclocked and running stable at 3.5GHz with the FSB at 1000 MHz. To achieve this I'm pumping 1.7V Vcore into the CPU. I'm using OCZ Gold Low Latency PC4000 RAM running at stock voltage and 2.5-3-3-7.

In other words I'm not overclocking my high performance RAM, only the CPU. The RAM is running at its stock speed and voltage for DDR500 and is still covered by OCZ warranty; in fact OCZ allow 10% headroom in RAM voltage without busting the warranty.

Thers a good article about this here.

:cool:

TOG

-TangleFoot-

Just a side note:

marka87uk wrote:

http://www.scan.co.uk/Products/ProductInfo.asp?WebProductID=121514
- This is really cheap - 1GB DDR2/PC4200 RAM.

That's DDR2 RAM, and wouldn't even fit in your chosen motherboard anyway!