I have been reading the
Digital AXPpci 33 Alpha PC Motherboard OEM Design Guide
that is available from the Digital archives. This is the revised
version of June1995, that includes the information of the 233 MHz
board/CPU. It leaves me with some small questions about my new
Alpha AXPpci33 with 21066A (233 MHz), to be purchased after
the September announcement of the European price, during the
Decus in Dublin.
Quote from page 1-3, Table 1-2, SPECint92, SpeCfp92,
DhrystoneVI, and Whetstone Performance Metrics
| ... Dhrystones VI
| DECchip 21066 166 MHz .... 333,374 ...
| DECchip 21066A 233 MHz .... 263,012 ....
Given this comparison, should the number of dhrystones for
the 21066A be in the range of 460,000 (233/166*333374)? And if
not, why is that?a
Quote from page A-5, Table A-3, Accessories and Suppliers:
| Cache
|32k x 8, 15ns, 28-pin DIP ...
|32k x 8, 20ns, 28-pin DIP ...
|128k x 8, 15ns, 28-pin DIP ...
|128k x 8, 20ns, 28-pin DIP ...
I have had suggested that the 256kB cache at 15ns would
be preferable (performance/price-wise). Any comments?
I don't know any price impact of going for 1024kB at 15ns,
nor do I know of any performance impact of option for
256kB at 20ns, or even no-cache, but I'd like to learn.
Quote from page 3-4, Tables 3-6, 3-6 and 3-7,
DECchip 21066A (233 MHz) Cooling using Low-Profile Heatsink
| ... max ambient temp ... 13-52 C
DECchip 21066A (233 MHz) Cooling using High-Profile Heatsink
| ... max ambient temp ... 20-66 C
DECchip 21066A (233 MHz) Cooling using Fan/Heatsink
| ... max ambient temp ... 54 C
Depending on the Air Velocity (in LFM whatever that is),
there is a range of maximum ambient temperatures. Best
reachable is with the high-profile heatsink, stables is with
the fan/heatsink combination. I prefer utter quiteness from
my computer. And I prefer to keep the machine going, whereas
in the attic where the machine will be located it may be
quite warm. I seem to lean to a High-profile heatsink.
Comments, please?
I warmly welcome any discussion about these questions. Direct
mail that I'll receive on this subject, I'll summarize here.
met vriendelijke groeten, Wim van Dorst
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Blue Baron = Wim van Dorst, Voice (+31) 33 676365, (+31) 2152 42319
(-: baron@clifton.hobby.nl WvD@Chem.AkzoNobel.nl :-)
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