Date: Sun, 7 May 1995 19:52:58 -0700 (PDT) From: "Rodney W. Grimes" <rgrimes@gndrsh.aac.dev.com> To: tb@emi.net (Thomas Bagli) Cc: freebsd-hardware@FreeBSD.org Subject: Re: Intel 'ZAPPA' motherboard -details? Message-ID: <199505080252.TAA15618@gndrsh.aac.dev.com> In-Reply-To: <199505080151.VAA00617@florence.emi.net> from "Thomas Bagli" at May 7, 95 09:51:02 pm
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>
> In a previous encounter, Rodney W. Grimes writes:
> >
> > EDO stands for Extended Data Out, I don't have any technical books
> > that cover just what changed in the DRAM design at this time, though
> > my new set of Micron Technology memory books shipped on Thursday so
> > I will have the ``official'' story very soon.
> >
> > My current understanding is that EDO simms basically hold valid data
> > on the output after RAS has been brought inactive, this allows you
> > to start the RAS precharge time early, effectively eliminating the
> > difference between access and cycle times on DRAM.
>
> Not that I believe everything I read, but the word is from some test
> lab that the difference between EDO and conventional memory shows no
> significant change in systems or graphic performance. The tests were,
> of course, DOS/Windows tests. Let us know what you find out.
Here are some numbers for you to see that infact there is a measurable
difference between standard simms and EDO simms, you just have to test
for specific things. Stuff like the Windows/DOS benchmarks are so tuned
to run out of a 256K cache that it makes me sick:
This is from a memory benchmark posted to -hackers by Bruce Evans, changed
by L Jonas Olsson, and then changed again by Bruce Evans to correct for
an extra store operation per loop. This is basically 4 x 32 bit memory
read or write test per iteration of the loop written in assembler.
First a set of test comparing the Intel Neptune chip set to the Intel
Triton chip set:
Board: ASUS PCI/E-P54NP4 Board: ASUS PCI/I-P54TP4
CPU: P54C-90 CPU: P54C-90
Cache: 256K-15nS SRAM Cache: 256K-15nS SRAM
Memory: 32MB Fast Page Mode Memory: 32MB Fast page mode
-DBDE_ORIGINAL -DCORRECTED -DBDE_ORIGINAL -DCORRECTED
1024: 204081633 bytes/sec 1024: 208333333 bytes/sec
2048: 212765957 bytes/sec 2048: 227272727 bytes/sec
4096: 227272727 bytes/sec 4096: 227272727 bytes/sec
8192: 204081633 bytes/sec 8192: 217391304 bytes/sec
16384: 103092784 bytes/sec 16384: 101010101 bytes/sec
32768: 89285714 bytes/sec 32768: 104166667 bytes/sec
65536: 89285714 bytes/sec 65536: 80000000 bytes/sec
131072: 86206897 bytes/sec 131072: 90090090 bytes/sec
262144: 71942446 bytes/sec 262144: 76923077 bytes/sec
524288: 65789474 bytes/sec 524288: 66666667 bytes/sec
1048576: 60240964 bytes/sec 1048576: 62111801 bytes/sec
2097152: 59880240 bytes/sec 2097152: 62111801 bytes/sec
4194304: 56179775 bytes/sec 4194304: 60606061 bytes/sec
8388608: 52910053 bytes/sec 8388608: 57471264 bytes/sec
16777216: 41493776 bytes/sec 16777216: 52356021 bytes/sec
-DLJO_WRITE_NOCACHE -DCORRECTE -DLJO_WRITE_NOCACHE -DCORRECTED
1024: 23201856 bytes/sec 1024: 37735849 bytes/sec
2048: 23255814 bytes/sec 2048: 38022814 bytes/sec
4096: 23255814 bytes/sec 4096: 37735849 bytes/sec
8192: 23255814 bytes/sec 8192: 38022814 bytes/sec
16384: 23148148 bytes/sec 16384: 38022814 bytes/sec
32768: 23148148 bytes/sec 32768: 38022814 bytes/sec
65536: 23148148 bytes/sec 65536: 37593985 bytes/sec
131072: 23201856 bytes/sec 131072: 37735849 bytes/sec
262144: 22988506 bytes/sec 262144: 37313433 bytes/sec
524288: 23148148 bytes/sec 524288: 37735849 bytes/sec
1048576: 23041475 bytes/sec 1048576: 37453184 bytes/sec
2097152: 22883295 bytes/sec 2097152: 37313433 bytes/sec
4194304: 22831050 bytes/sec 4194304: 37037037 bytes/sec
8388608: 22675737 bytes/sec 8388608: 36496350 bytes/sec
16777216: 22371365 bytes/sec 16777216: 35087719 bytes/sec
-DLJO_WRITE_CACHE -DCORRECTED -DLJO_WRITE_CACHE -DCORRECTED
1024: 238095238 bytes/sec 1024: 250000000 bytes/sec
2048: 256410256 bytes/sec 2048: 270270270 bytes/sec
4096: 263157895 bytes/sec 4096: 263157895 bytes/sec
8192: 243902439 bytes/sec 8192: 227272727 bytes/sec
16384: 62111801 bytes/sec 16384: 55555556 bytes/sec
32768: 57471264 bytes/sec 32768: 55555556 bytes/sec
65536: 61349693 bytes/sec 65536: 50000000 bytes/sec
131072: 47169811 bytes/sec 131072: 45871560 bytes/sec
262144: 37453184 bytes/sec 262144: 42918455 bytes/sec
524288: 30395137 bytes/sec 524288: 40160643 bytes/sec
1048576: 29239766 bytes/sec 1048576: 38167939 bytes/sec
2097152: 28735632 bytes/sec 2097152: 38314176 bytes/sec
4194304: 28571429 bytes/sec 4194304: 37593985 bytes/sec
8388608: 27777778 bytes/sec 8388608: 37313433 bytes/sec
16777216: 26809651 bytes/sec 16777216: 36231884 bytes/sec
And now the TP4 using EDO memory and the cache turned OFF (running with
the cache on seems to defeat any benifit from the EDO memory due to
the delay waiting for the cache miss to start main memory). I do not
know if this holds true when you use the pipelined burst cache. The
real thing that EDO memory was meant to do was to replace the cache
in Notebook computers, since SRAM cache's eat a lot of power. I know
running my Trition machine with EDO memory and the cache turned off
feals just like it does with standard memory and the cache on.
Board: ASUS PCI/I-P54TP4
CPU: P54C-90
Cache: 256K-15nS SRAM (Disabled)
Memory: 16MB EDO
-DBDE_ORIGINAL -DCORRECTED
1024: 217391304 bytes/sec
2048: 227272727 bytes/sec
4096: 227272727 bytes/sec
8192: 185185185 bytes/sec
16384: 64516129 bytes/sec
32768: 64516129 bytes/sec
65536: 64516129 bytes/sec
131072: 64516129 bytes/sec
262144: 64102564 bytes/sec
524288: 62500000 bytes/sec
1048576: 62500000 bytes/sec
2097152: 61728395 bytes/sec
4194304: 58823529 bytes/sec
8388608: 54054054 bytes/sec
-DLJO_WRITE_NOCACHE -DCORRECTED
1024: 37313433 bytes/sec
2048: 37878788 bytes/sec
4096: 37878788 bytes/sec
8192: 37878788 bytes/sec
16384: 37878788 bytes/sec
32768: 37735849 bytes/sec
65536: 37593985 bytes/sec
131072: 37735849 bytes/sec
262144: 37313433 bytes/sec
524288: 37313433 bytes/sec
1048576: 37174721 bytes/sec
2097152: 36900369 bytes/sec
4194304: 36496350 bytes/sec
8388608: 34364261 bytes/sec
-DLJO_WRITE_CACHE -DCORRECTED
1024: 232558140 bytes/sec
2048: 250000000 bytes/sec
4096: 270270270 bytes/sec
8192: 217391304 bytes/sec
16384: 38759690 bytes/sec
32768: 39525692 bytes/sec
65536: 39525692 bytes/sec
131072: 39370079 bytes/sec
262144: 38610039 bytes/sec
524288: 38910506 bytes/sec
1048576: 38461538 bytes/sec
2097152: 38610039 bytes/sec
4194304: 36496350 bytes/sec
8388608: 18148820 bytes/sec
--
Rod Grimes rgrimes@gndrsh.aac.dev.com
Accurate Automation Company Custom computers for FreeBSD
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