768Mb on 503+

?uzzled wrote:

 > I've now got my hands a double sided 512Mb PC133 DIMM. Potentially, I could
 > run my system with 768Mb of RAM. Is this worth doing ? I know my system
 > only caches 256Mb but could the other 512Mb be put to use ? (I've already
 > disabled the virtual memory).
 >
 > My one major concern is, will the 512Mb DIMM draw too much power ? (We stuck
 > some PC133 memory into some PIII boards at work and knackered them. Now
 > going back to PC100 memory, the machines still crashes.) Has anybody used a
 > 512Mb DIMM in their machine ? (The manual only shows potentially 2 X 256Mb
 > [as even 256Mb DIMMs weren't out when it was printed.])
 >

.


Your board won't support a 512MB DIMM. Your board might recognize only half of
this DIMM, or it might not work at all.

The Via Apollo MVP3 chipset on your motherboard, supports memory chip densities
up to 128Mbit. DIMM sizes up to 256MB can be used. These 256MB DIMMs must
have sixteen 128Mbit chips--eighteen chips if ECC.<!-- ~MESSAGE_AFTER~ -->
 >> Stay informed about: 768Mb on 503+ 

OK, thanks guys. Better not risk it then.
 >> Stay informed about: 768Mb on 503+ 

How did you get the two 256 pc133 dimms to work.? I put two in and the
machine only recognizes 128 meg RAM. Is it the bios? I am using an FIC 503+
board for years and no trouble except I can't add two 256 dimms. Any
suggestions would be appreciated. Thank you
byrne62 DeleteThis @sbcglobal.net
 >> Stay informed about: 768Mb on 503+ 

It's probably the memory modules you are using. I believe the MVP3 chipset can
only handle up to 16 MB per individual memory chip. That would mean that a 256
MB DIMM would require 16 chips (double-sided, 8 chips on each side). Other
chipsets from the same period, like the Intel 440BX, have the same limitation.

Unfortunately, these DIMMs are getting harder to come by. Most 256 DIMMs on the
market these days have 8 32MB chips. This often causes the computer to
recognize only half the memory, as seems to be your case.

--Alex


"William M. Byrne" wrote:

 > How did you get the two 256 pc133 dimms to work.? I put two in and the
 > machine only recognizes 128 meg RAM. Is it the bios? I am using an FIC 503+
 > board for years and no trouble except I can't add two 256 dimms. Any
 > suggestions would be appreciated. Thank you
 > byrne62.TakeThisOut@sbcglobal.net<!-- ~MESSAGE_AFTER~ -->
 >> Stay informed about: 768Mb on 503+ 

you need low density sdram chips for compatibility with the mvp3
chipset. IOW, your 256 meg sticks should have 16 chips on them.

--
Best regards,
Kyle
"William M. Byrne" <byrne62.TakeThisOut@sbcglobal.net> wrote in message
news:8dvBb.68652$0p3.22958@newssvr25.news.prodigy.com...
| How did you get the two 256 pc133 dimms to work.? I put two in and
the
| machine only recognizes 128 meg RAM. Is it the bios? I am using an
FIC 503+
| board for years and no trouble except I can't add two 256 dimms.
Any
| suggestions would be appreciated. Thank you
| byrne62.TakeThisOut@sbcglobal.net
|
|
 >> Stay informed about: 768Mb on 503+ 

The DIMMs are double sided DIMMs with 8 chips on each side. Sticker on the
DIMM shows:
PC133 256Mb SDRAM 16MX8 SPD
U19256A4UIB6320
*0300816*29

The chips themselves show:
16M864-PB20T
0329

And the barcode shows:
256u16s168-75

A search on google for the barcode provides:
<a style='text-decoration: underline;' href="http://www.megacomp.fi/tuotteet_pc_muistit.html" target="_blank">http://www.megacomp.fi/tuotteet_pc_muistit.html</a>

The BIOS I'm using is JE4333. Everything in the BIOS pretty much enabled if
it looks like it will increase performance, including CL2, 4 bank interleave
and RAM timings to Turbo.

I think for it to work, you need low density (double sided) DIMMs for all
the memory to be recognised. However, you will see a performance hit (as
asked in my original post '512Mb on VA-503+'). I was getting 48fps in Quake
3 with a Voodoo 3 and 256Mb but that dropped to 42fps with 512Mb. However, I
was able to turn off virtual memory and apps run quicker.

Hope that has helped you.


"William M. Byrne" <byrne62 DeleteThis @sbcglobal.net> wrote in message
news:8dvBb.68652$0p3.22958@newssvr25.news.prodigy.com...
 > How did you get the two 256 pc133 dimms to work.? I put two in and the
 > machine only recognizes 128 meg RAM. Is it the bios? I am using an FIC
503+
 > board for years and no trouble except I can't add two 256 dimms. Any
 > suggestions would be appreciated. Thank you
 > byrne62 DeleteThis @sbcglobal.net
 >
 ><!-- ~MESSAGE_AFTER~ -->
 >> Stay informed about: 768Mb on 503+ 

"?uzzled" <not.TakeThisOut@got.one> wrote in message news:<br7rrg$eou$1@sparta.btinternet.com>...

 > I think for it to work, you need low density (double sided) DIMMs for all
 > the memory to be recognised. However, you will see a performance hit (as
 > asked in my original post '512Mb on VA-503+'). I was getting 48fps in Quake
 > 3 with a Voodoo 3 and 256Mb but that dropped to 42fps with 512Mb. However, I
 > was able to turn off virtual memory and apps run quicker.


If you use a K6-III, K6-2+, or K6-III+, the processor's L2 will
work-around the VA-503+ (and all other Socket 7 chipsets) cacheable
RAM limit, permitting utilization of your 512MB~768MB with no virtual
memory penalty.

Regards,

Tim<!-- ~MESSAGE_AFTER~ -->
 >> Stay informed about: 768Mb on 503+