/ NSTL Lab Report, December 1994
Drive Bays And Slots Galore...
$3999 system doesn't have exceptional overall Unix performance
results, but it had high intermark and above average X Window System
scores, due in part to its fast graphics subsystem. The XiP90 MTower
SP utilizes a mini-tower design that houses seven expansion slots
(four 16-bit and three PCI local bus), as well as 10 drive bays (six
3 1/2 inch and four 5 1/4 inch). On the downside, the XiP90 MTower
SP may frustrate some users because its drive bays and SIMM banks
block several expansion slots. These
blocked slots cannot be used for full-length adapters but are fine
Price As Tested
latest incarnation of Intel's Pentium processor does more than
simply run faster than the older 60- and 66-MHz versions. In fact, along
with the availability of Windows NT 3.5 the latest Pentium should
make dual-processor architectures a cost- effective option in the
desktop workstation market. The P54C Pentium runs faster, comes in a
smaller package, operates at 33.V.
and adds special support for dual processor designs. High- end
multi-processor systems implement a dedicated cache for each processor,
but sharing a single-processor cache between two processors enables
a simpler, less expensive dual processorarchitecture.
The system requires only one SRAM (static RAM) cache and a single
cache controller. However, additional logic is also needed to
arbitrate access to the shared bus and ensure cache coherency.
NTower DP- Dual processors with heat sinks
P54C Pentium has built-in hardware features to support cache
coherency and bus arbitration. Vendors can now implement a
dual-processor archi- tecture without worrying about
designing additional logic to arbitrate a shared cache.
Computer's XiP90 NTower DP
came to us
with an extra processor installed (above-left). Other units came
with open slots for dual-processor upgrades. As the XiP90 proves,
you can now buy a surprisingly low cost dual processor system. Or
you can buy an upgradeable model and pop in the second processor if
your needs demand it. Of course, your software application must
support dual processing, Our standard low level and application
level benchmarks do not exercise a second processor, so any
performance enhancement effected by a dual-processor design will not
show up. This brings us to the second development that should boost
the market acceptance of dual-processor systems: Windows NT. NT was
built from the ground up to support multiple processors. The NT
kernel will spawn threads to each available processor. It simply
allocates a dedicated processor to the next-highest priority thread.
New multi-threaded NT applications, such as Picture Publisher, do
not have to do anything special to take advantage of a dual
processor. You run different threads for complex operations (e.g..
applying a special-effects filter), and NT will do the rest.