( ESNUG 349 Item 2 ) --------------------------------------------- [4/18/00]
From: Erik Jessen <ejessen@vixel.com>
Subject: Older, Cheaper VCS Versions Benchmarked *Faster* Than New VCSi !!
Hi, John,
We use Windows NT with VCSi version 4.1.1. I did some benchmarking with
VCS and VCSi 5.1 (which is supposed to be a LOT faster than 4.1.1). My
results on NT were:
- VCSi 5.1 (with radiant-2) was 3X *SLOWER* than VCSi 4.1.1
- VCS 5.1 (with radiant-2) was 30% faster than VCSi 4.1.1
(but costs 2x VCSi).
I spent several weeks running tests in coordination with the Synopsys.
Finally, the VCS FAE found out what happened. Back when Viewlogic released
VCSi 4.1.1, they forgot to turn off all the optimization algorithms, so VCSi
4.1.1 was really like VCS 4.X. All subsequent releases of VCSi have had
those optimizations turned off, which is why VCSi 5.1, even with max
optimization turned on, is so much slower. :)
Another useful tidbit: We normally use SignalScan to dump out a waveform
database, and then view it. I tested out VCS' new one (that doesn't use
PLI); I saw a 7X speedup over using SignalScan/PLI.
That's pretty significant!
I've also been toying with the idea of writing to you about how good the
VCS support has been for us. They've made handling these problems a
breeze for us and I'd like to publically acknowledge that. I'm at a small
startup, so it's not like we're a big account that has to be taken care of,
yet we're treated like kings by these guys! Great support!
- Erik Jessen
Vixel Irvine, CA
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