Regarding the CPU & RAM bus speed

A lot of people get confused by this so don't worry. CPU's run quad pumped which means they send info 4 times per clock so a CPU with a 1333FSB is actually running at 333x4. DDR (Double Data Rate) RAM sends info twice per clock so in order to run 1:1 with your 1333FSB you would need DDR2 667 which when run in dual-channel is running at 1333. The reason most opt for DDR2 800 or higher is for overclocking because with RAM that speed you can run your CPU up to 1600FSB before you need to start overclocking the RAM.

Take my setup for instance, I have a E6300 overclocked to 1600FSB and DDR2 800 running 1:1 with the CPU. For you I would just look for inexpensive, quality DDR2 667 RAM.

I know your not from the US but just to give you an idea what to look for this http://www.newegg.com/Product/Product.aspx?Item=N82E168... is a great product and very inexpensive after rebate

and this http://www.newegg.com/Product/Product.aspx?Item=N82E168... is another one which is good and has slightly better latency.

If you're still confused by the excellent advice above,
here's how to simplify these concepts:

On Intel systems ...
800 means one thing for the Front Side Bus and
800 means a different thing for the memory bus
because the Northbridge has 2 busses:
one to the CPU and one to the RAM.

Let's start with RAM:

DDR2-800 means an effective clock rate of 800 Mhz;
but, the "frequency" of the RAM clock is only 400 MHz,
because "DDR" means Double Data Rate: data is transmitted
twice for every tick of that memory bus clock.


And now for the CPU:

A rated FSB of 800 MHz means a raw bus speed of 200 MHz,
because the Front Side Bus sends data 4 times for every tick
of that CPU bus clock. That's just the way that Intel chipsets
and Intel CPUs are designed to operate together.

Thus, our workstations here have a very common setup:
200 MHz "Bus Bpeed" x 4 = 800 MHz "Rated FSB" and
400 MHz "DRAM frequency" x 2 = DDR2-800 .

And, because 16 bytes are transmitted for every raw tick
of the DRAM clock, or 8 bytes transmitted for each effective
tick of the memory bus, 400 x 16 = DDR2-800 x 8 bytes = 6,400 MB/sec.


Thus, the memory bandwidth of our common systems is 6.4 GB/second
(i.e. 6,400 megabytes per second).

That is why DDR2-800 is also known as PC2-6400 i.e. 6400 MB/second.


If you download and install CPU-Z, you can standardize
on the measurements it reports: on the above setup
the "Bus Speed" is reported to be 200 MHz and
the "DRAM Frequency" is reported to be 400 MHz,
for an FSB RAM ratio of 1:2.

Some folks like to refer to 800:800 as "1:1", but
that computation conflicts with the convention
used by the CPU-Z software.

It is highly recommended that we standardize on the
terminology reported by CPU-Z, because that
software is in such widespread use.


I hope this helps.


Sincerely yours,
/s/ Paul Andrew Mitchell
Webmaster, Supreme Law Library
http://www.supremelaw.org/