[TUHS] Old mainframe I/O speed (was: core)
krewat at kilonet.net
Mon Jun 25 01:47:32 AEST 2018
On 6/24/2018 10:41 AM, Lawrence Stewart wrote:
> Glue or microcode NOPs or DRM licence unlock codes work, but they tend to damage your reputation.
I was called in at the last minute to help a consulting firm who was
having a hard time convincing their customer that they knew what they
were doing. They spec'd out a SunFire 4800 cluster back in the mid
2000's that would run 10 or so medium-to-large OLTP and DW Oracle
instances. I came across the notion of "Capacity On Demand" (COD) CPU
licensing. You would buy a complete system, full of CPUS and memory, but
only license a subset of the CPUs (and associated memory).
The customer thought "great!" we can save a few $'s and if we want, we
can turn on the extra capacity when/if we need it.
After reading all the documentation, I was on a conference call with
some Sun engineers, the sales rep, and my customer's team (including
some of the consultants who were a little too "wet behind the ears".
I point-blank asked the engineers: "I see in the documentation that if
you use COD, memory interleaving is turned off, which only makes sense.
Since we're only licensing 3 of every 4 CPU, Doesn't that mean we're
only going to get half if not one quarter of the platform's advertised
memory bandwidth?" (Single vs. two-way vs. four-way interleaving. Odd
number of CPUs, no interleaving). Reluctantly, one of the engineers
agreed that was indeed the case. The other "engineers" had no freakin'
clue, but muttered something about "we have to remember that for next
I roughly calculated the difference in my head and said: "For an extra
2% of the entire project cost (IBM Shark, Oracle licenses and Sun
hardware combined), we're going to hobble these systems that much?".
After the consulting firm I was sub-contracting for balked on telling
the customer about this extra cost, I mentioned this in the presentation
for the customer's CIO. She perked up her ears and immediately said
'We'll spend the extra for that much performance. What were you guys
thinking?'" (referring to the original consulting firm's own "Sun
expert" who I'd had a lot of arguments with, actually quit the day they
signed the contract with Sun).
I wonder, to this day, how many Sun customers were sold this COD concept
only to suffer through 1/2 or 1/4 the memory bandwidth. This was for the
entire SunFire 3800/4800/4810/6800/E12K/E15K line.
I went on to support that system for 5 more years as the customer
wouldn't let the consulting firm even THINK of letting me leave ;)
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