Datasheet

Technique 1: Experiencing the Windows Experience Index
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processor-intensive tests involving data compres-
sion and decompression, encryption and decryption
(AES and SHA1), and encoding video. Then a secret
formula gets applied to translate the results into a
score between 1.0 and 5.9.
Worth noting: Traditional CPU-intensive opera-
tions like, oh, running Fast Fourier Transforms
or recalculating humongous Excel spreadsheets
or festering automatic color calibrations in
Adobe Illustrator aren’t considered when com-
ing up with the WEI processor score. If you
spend a lot of time working with big spread-
sheets, assembling book-size manuscripts,
or doctoring photos for presentation to
Congressional subcommittees and/or way-
ward spouses — to say nothing of searching
for oil — your impression of processor speed
may vary greatly from Vista’s.
Memory (RAM) Component
The Memory (RAM) Component score supposedly
reflects memory operations per second, but heaven
help ya if you base a RAM-buying decision on that
fallacious description.
Two competing RAM limitations are at work here:
the speed at which Vista can shuffle data into and
out of memory and the total amount of memory
available for shuffles. It’s hard to come up with
a single number that encapsulates both aspects
of RAM performance, so WinSAT basically punts.
Here’s how:
1.
WinSAT tests the throughput — the total num-
ber of megabytes per second — of large blocks
of data going into and out of system memory.
A magic incantation translates the bandwidth in
megabytes per second into a raw score between
1.0 and 5.9.
2.
Then WinSAT caps the score based on the total
amount of memory available to the PC, minus
any memory that’s reserved for graphics. If
you don’t have “enough” memory, your mem-
ory speed score gets cut off at the knees.
The caps appear in Table 1-1.
Maxing out the WEI
As Vista slid out the door, Microsoft decided
to place an arbitrary upper limit on perform-
ance ratings: the day Vista hit the stands,
every PC scored at least a 1, but the fastest,
most capable, bestest components maxed out
at 5.9. You could assemble a hive of 64,000
optically interlinked supercomputers operating
at Bose Einstein temperatures, with petabytes
of L2 cache and yottabytes of solid-state disk,
and the self-aware über-computer would have
to admit (no doubt in sheepish tones) that its
Windows Experience Index doesn’t exceed
5.9. It’s a design requirement. Douglas Adams
would be proud.
Microsoft promises that we can continue to count
on the WEI because
 The WEI component score you get today will be
the same WEI you get tomorrow. If you have a
PC with a Gaming Graphics score of 4.8, it will
always score 4.8.
 As technology improves, WEIs will be allowed to
increase. By the year 2008, we should see WEIs
of 6 or 7. Kind of like the open-ended Richter
scale. In the year 2525 . . .
That said, there’s no claim for scalability: a PC with
a WEI of 7 won’t necessarily run two (or ten) times
faster than one with a WEI of 6.
Breaking down components
Vista includes terse descriptions of each of the five
performance components in the Performance
Information and Tools dialog box (refer to Figure 1-1).
The method for calculating each of those five com-
ponents goes way beyond wiggling your PC’s fingers
and toes — and the descriptions leave much to be
desired.
Processor Component
Vista says that the Processor Component is rated
by calculations per second, but that’s only part
of the story. In fact, WinSAT runs a battery of
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