Memory is one of the most critical
system components in any computer. The particular type of
memory that I am referring to is also known as RAM (Random
Access Memory). It is RAM that has allowed computers in the
past and present to operate at such snappy speeds. You can
picture RAM as one big buffer used to store any data
temporarily for ultra fast access from the CPU (Central
Processing Unit) or other components, allowing such
component to go about its business with minimal delay.
Given that virtually everything on a
computer travels through RAM at some point in time, it is a
heavily used component. For example, the Internet browser
you are using to read this very article is using some of the
system memory. In fact, Internet browsers tend to use a
large amount of system memory, particularly if multiple
pages are open at the same time. So if your computer was to
have cheap generic or faulty memory, the Internet browser
may occasionally “crash” forcing it to shut down.
When building a new computer users may
skimp on the all important memory component. Rather than buy
a trusted brand name they may go with the cheaper unknown.
Usually this cheap generic memory is not guaranteed to
operate at specific timings and compatibility is also quite
poor. These cheap memory modules are more often than not
designed for single channel use, and will create problems
when used in dual-channel environments. Therefore my advice
to anyone building a new computer is to make sure the memory
purchased is of a well known and respected brand name.
Luckily nowadays there are plenty of
trustworthy manufacturers to choose from; not only that but
you will find a wide range of products targeted at gamers
and overclockers, value-minded consumers, as well as for
those building a server, where stability is even more
important than speed.
For the purposes of our article we
picked modules from Corsair Memory, one of the most
reputable brands in the business. Like many other
manufacturers such as Crucial, Kingston, and Mushkin, to
name a few, Corsair offers what they call “Value Select”
memory along with other more expensive modules.
You will see regularly in our forums
readers asking questions such as “Which Corsair memory
should I buy XMS or Value Select?” Like most questions of
this nature there is no simple ‘yes’ or ‘no’ answer that
will apply to everyone. First things first, users need to
know why Corsair offers the more expensive XMS memory and
what it does.
XMS vs. Value Select
The Corsair XMS series is designed to be
the ultimate performance solution. This means XMS memory is
going to cost more than the regular Value Select memory,
considerably more. While a pair of 512MB sticks of Corsair
Value Select memory sells for roughly
$85, XMS versions can
go from $120 to
up to $200 depending on its latency. It
should be made clear however that ‘Value Select’ memory is
nothing like generic memory, it is indeed much better in
terms of quality and compatibility. In comparison, a pair of
512MB sticks of generic memory will set you at $70,
nevertheless the $15 saving is not worth the risk.
Back to the Value Select, you should
note there can be some variation in the timings, those with
model names that end with a C3 are designed to operate at
CAS3. Anything not labeled should work without a problem at
CAS2.5 and I have found this to be the case with several
modules. Corsair does not specify the exact memory timings
in these modules but the memory is configured by the BySPD
setting. The Value Select memory is also capable of
operating in dual-channel configurations without requiring
more voltage.
When it comes to overclocking and
improved timings the Value Select memory does come with a
lot of uncertainties. More often that not I would imagine
this memory is unable to operate much higher than its
designed frequency. This is of course where the more
powerful XMS memory comes into play. Corsair guarantees the
timings of their XMS memory along with their overclocking
frequency. For example XMS memory specified to operate at
DDR500 with CAS2.5-4-4-8-T1 timings will do just that. Even
DDR400 XMS memory with CAS2-2-2-5-T1 timings is guaranteed
to do so in single channel and dual channel environments.
Bottom-line is XMS memory modules will
operate at their advertised specifications as long as the
computer they are being used in can support them. For
example DDR550 memory can only operate at 550MHz if the
processor can achieve a 275MHz FSB. Clearly overclocking is
a huge driving force behind the XMS series. However, it’s
not the only reason for this memory type to exist. Gamers
are a very demanding bunch and only the very best
performance will do. So those seeking the ultimate in memory
technology will be seeking this kind of memory.
However, while XMS memory is aimed at
computer enthusiasts, it is not necessarily going to give
games a huge performance advantage over those using the
cheaper Value Select memory. In fact, as long as the memory
bandwidth results are around 6GB/s an AMD Athlon 64
processor operating on the standard 200MHz FSB will have
more than enough bandwidth. Memory bandwidth has a greater
effect on extremely CPU intensive programs such as DVD
encoding. Here a 7% increase in bandwidth will account for
quite a lot, where as games will only see a 1-2 fps
increase. Anyway, let’s move to the benchmarks to see the
actual results.
