From: kanefsky@halcyon.com (Steve Kanefsky)
Subject: Re: Daystar Powercache (need info...)
Organization: The 23:00 News and Mail Service
Date: Tue, 15 Sep 1992 15:38:06 GMT

In article <39892@imag.imag.fr> oueichek@ngulu (Ibaa Oueichek) writes:
>Steve Kanefsky (kanefsky@halcyon.com) wrote:
>: 
>: 
>: My guess is that with the FPU, the LC II with 50mhz PowerCache would be 20-
>: 30% slower in all the CPU and math-related benchmarks.  The disk benchmarks
>: seem to be limited in both cases by the disk itself (virtually identical
>: readings) so we can't tell how much better the Quadra might be without
>: faster disk drives.  The graphics performance of the Quadra seems to be
>: the big difference, and you can't even put a graphics card in the LC II
>: once the accelerator is in there.
>
>  Well, what about an old MacII, or IIx ?. They have plenty of slots, and i
>  think they shouldn't be really expensive. 

Yes, putting a PowerCache in an old MacII or IIx would give you the
performance and the expandability.  If I had an old II or IIx I'm sure I
would have done that, but I wasn't interested in buying a used machine.
Since the PowerCache is universal and you can swap adaptors for free, I
figure I can upgrade to an expandable machine (something like the Performa 600
for example) and keep all the performance of the PowerCache.

>: I expect that the 33mhz '040 PowerCache due out soon will beat the
>: Quadra 700 and 900 on the Math and CPU related stuff, and be very close to
>: (possibly even ahead of) the Quadra 950 in these areas.  The 16-bit data
>: path of the LC II has very little effect once you go to an external
>: cache.
>  Well, it depends, most of the benchmarks are based on loops and very small
>programs that they fit in a very small cach. Something which is rarely the
>case with real-life applications.

Not true.  Even in "real-life," there's an 80-90% cache hit rate.  My
real-world benchmarks seem to agree with this.  The benchmarks predict
fairly accurately the overall performance.  The CPU performance in the
benchmarks, for example, is about 3 times better.  Compiling about
150,000 lines of code in THINK C was 2.7 times faster, even though the
disk was only measured as 18% faster.


>:The Quadras will be somewhat faster in SCSI transfers (if you
>: have a fast enough disk to bring out the difference) and will be much 
>: better in graphics performance (not to mention the ability to drive big 
>: monitors). Naturally the Quadras have a lot of expansion capabilities 
>: (including RAM) that the LC II doesn't have.  Nevertheless, for tons of 
>: raw power in a very small box for relatively little money, I can't see how 
>: the LC II/PowerCache combo can be beat.
>
>  Well, again : What about a MacIIx + '040 Power Cache + SuperMac Thunder + a
>fast SCSI card ?. You still have plenty of slots, and a machine that will put
>a Quadra 900 in the garbage dump. But i think a Q950 costs less than the
>combinaison above.

Yes, even for a little more money I'd rather have a well-integrated Q950
than a Frankenstein MacIIx.  I was talking about a cost-effective way to
have the processing power (if not the graphics or disk throughput) of a Q950 
without the size or cost.

I'm not 100% certain that the 50mhz '030 or 33mhz '040 PowerCache is the
most cost-effective solution.  The 33mhz and 40mhz '030 PowerCaches are
much cheaper and aren't that much worse performance-wise.  
The 33mhz costs only half as much and should still double the pefromance
of the LC II.  If I were smart I'd probably have gotten the 33mhz and a
240MB hard disk for the same price as the 50mhz (heck, I'm even still
running on 4MB RAM).  I'm just one of those guys that can't resist
getting the best if I can manage it.  So instead of getting a good
accelerator and a good disk drive, I'm getting the best accelerator 
(by taking advantage of the special upgrade to the '040 when it comes out) 
and I probably won't get a disk drive until I can afford one of the best of 
those.


--
Steve Kanefsky


Newsgroups: comp.sys.mac.hardware