Sun's StarCat vs IBM's Regatta
How IBM Enterprise Unix Servers Might Stack Up
By Timothy Prickett Morgan
DATE: 08/22/2001
Call it Christmas in August. IBM Corp is apparently starting to talk to
business partners and customers about the expected performance they can expect
from the Power4-based "Regatta" servers. One person who has seen some of the
preliminary performance estimates that IBM has put together for the current and
future Unix server lines from IBM, Sun, HP and Compaq, sent me a bar chart that
shows the lay of the land when it comes to online transaction processing as
gauged by the TPC-C benchmark test.
IBM almost certainly wants to keep this information from reaching customers
right now, especially as it is trying to sell the current generation of "Turbo
Condor" pSeries 680 servers during the entire third and most of the fourth
quarter of 2001. IBM is not interested in getting into a position of providing
a warranty of any performance level for the Regattas, naturally enough when you
consider that they won't be announced for a few months yet.
Nonetheless, as readers of ComputerWire are well aware, plenty of people have
been making their own assessments of how IBM's Regatta, Sun's "StarCat"
Enterprise 15000, HP's Superdomes, and Compaq's "Wildfire" GS320s will stack
up. Performance is one of the key drivers of business at the high end of the
Unix market, no matter how much any of these vendors protest otherwise.
IBM's estimates of the performance of these future Unix machines is
interesting, however thin the data those estimates are based on, because
experts at IBM are making the estimates. IBM's performance estimates are
consistent with those made by ComputerWire, which has people who also know how
to use basic algebra, common sense and fudge factors to try to reckon what a
future server might and might not be able to do.
In my conversations in recent months with various sources familiar with the
Regattas, my suspicion that the initial performance that IBM can deliver with
the 32-way Regatta machines would be lower than one might expect indeed turns
out to be true. Even though the Regatta borrows heavily on existing pSeries and
RS/6000 components, the machine has a radically different processor, memory,
interconnect backplane, and I/O architecture. So tuning the Regattas for peak
performance is going to take some time. Based on raw processor cycles, a
Regatta should be able to handle between 500,000 and 600,000 transactions per
minute on the TPC-C test, but it will take faster Power4 processors than IBM
will initially deliver and, more importantly, significant amounts of tuning to
hit that level.
Based on historical trends on the TPC-C benchmark on Unix machines, I reckoned
a few weeks ago that a Regatta using 1GHz or 1.1GHz Power4 processors should be
able to handle between 400,000 and 450,000 TPM. The latest information from
inside IBM more or less confirms this estimate. According to the IBM
competitive analysis, a fully loaded Regatta is pegged at about 420,000 TPM
right now. That number could increase significantly in the next two months.
That's almost double the 220,807 TPM that IBM has attained with the 24-way
pSeries 680 server using 600MHz S-Star processors.
IBM apparently reckons that a 24-way Sun Fire 6800 server using 750MHz
UltraSparc-III processors will handle about 165,000 TPM. Sun has yet to
announce any TPC-C benchmark results on its Sun Fire machines, saying that it
prefers to run real-world benchmarks like Oracle and PeopleSoft applications
instead. By not doing the benchmarks itself, Sun is leaving it up to people
with calculators and spreadsheets to make their own estimates, which is
probably just as dangerous as posting a solid but nonetheless not winning
benchmark result. Sun's latest TPC-C test on the 64-way "Starfire" Enterprise
10000 server using 400MHz UltraSparc-II processors pegged its performance at
156,873 TPM. IBM didn't do the math on this one, but using the new 466MHz
UltraSparc-II processors, a 64-way server should be able to hit about 185,000
TPM. IBM reckons that the kicker to the Starfire server, by which one assumes
IBM is referring to the 72-way StarCat server using 750MHz UltraSparc-III
processors, will be able to handle about 280,000 TPM. If this turns out to be
the case, the initial Regattas will have 50% more throughput than the initial
StarCats will deliver later this year.
The Compaq Wildfire servers, which are now shipping with 1GHz EV68 Alpha
processors, are the reigning champions of the TPC-C fight, with 230,533 TPM on
a 32-way machine. However, with essentially the same clock speed and number of
processing elements, the 32-way Regattas will offer about 80% more performance
than the current Wildfires. Lest you think the Regattas will always beat the
Wildfires hands-down, on certain technical workloads, Alpha-based servers
deliver greater performance than one would expect based on the TPC-C
benchmarks. This is especially true on HPC workloads. IBM often gets the
biggest peak theoretical performance for its press releases, but in the field
Compaq machines often deliver better bang for the buck and equivalent
performance. That said, Compaq is going to have to field some pretty impressive
hardware and do a substantial amount of tuning to beat the Regattas on the
TPC-C test, and probably on many other commercial data processing workloads.
If anyone has a chance of catching up with the Regattas, IBM appears to believe
that it is HP with its Superdomes. While the current Superdome server with 48
of HP's 550MHz PA-8600 processors could only handle 197,024 TPM, with proper
tuning this machine is probably able to handle 250,000 TPM using 64 of these
PA-8600 processors. Sources at HP, speaking earlier this year with
ComputerWire, hinted that fully loaded Superdomes with 64 PA-8700 processors
would be able to do about 50% more work than the early 48-way TPC-C test result
HP posted, which puts it at around 300,000 TPM, assuming the clock speed of the
PA-8700 used in the machine is 700MHz.
IBM reckons that a Superdome with the PA-8700 - clock speed unknown - will be
able to handle around 320,000 TPM with 64 processors. IBM may know that HP has
been able to crank the clock speed on the PA-8700s used in the Superdomes from
700MHz to 750MHz. HP said earlier this year that the PA-8700s will start at
around 600MHz and scale up to 800MHz or maybe even 900MHz (CI No 4,118) and
that they would start shipping in 8-way and 16-way N- class servers after
750MHz PA-8700s made their debut in the company's workstation line. Then again,
IBM might be guessing that HP will make more progress on tuning HP-UX and
Oracle for the TPC-C test. Either way, if IBM is right, the Regatta machines
will still offer about 30% more aggregate online transaction processing power.
Only time will tell if any of these estimates made by IBM's competitive
analysis people will pan out. timpm@computerwire.com
cbronline.com |
