List of 486 motherboards to work well with the Pentium Overdrive (POD) in write-back mode

Discussion about old PC hardware.

List of 486 motherboards to work well with the Pentium Overdrive (POD) in write-back mode

Postby feipoa » 2017-11-19 @ 15:23

I was thinking it might be beneficial to formulate a list of socket 2/3, 486-class motherboards which work well with the Pentium Overdrive (POD) in L1 write-back mode. And to a lesser extent, perhaps a list in which the POD works well in only write-through mode. And another list of boards which do not work at all with the POD.

From memory, I know the Biostar MB-8433UUD works very well with the POD in write-back mode; the PC Chips M919 v3.4, on the other hand, only works with the POD in L1 write-through mode.
User avatar
feipoa
l33t++
 
Posts: 5514
Joined: 2011-3-07 @ 13:54
Location: Canada

Re: List of 486 motherboards to work well with the Pentium Overdrive (POD) in write-back mode

Postby jesolo » 2017-11-19 @ 17:25

What's the best way to confirm (or how do you confirm) that your CPU is running in WB mode?
Or, will it simply refuse to boot if you jumper it on the motherboard into WB mode?
User avatar
jesolo
Oldbie
 
Posts: 1448
Joined: 2014-6-24 @ 19:04
Location: South Africa

Re: List of 486 motherboards to work well with the Pentium Overdrive (POD) in write-back mode

Postby mrau » 2017-11-19 @ 17:33

if i understand correctly writes will not be accelerated by cache when in write through? so speed measurements should help i suppose
mrau
Oldbie
 
Posts: 1002
Joined: 2015-11-28 @ 12:43

Re: List of 486 motherboards to work well with the Pentium Overdrive (POD) in write-back mode

Postby alvaro84 » 2017-11-19 @ 18:06

Is there a good and sure way to quickly test the cache in WB/WT mode? Or just watch out random instability?
Shame on us, doomed from the start
May God have mercy on our dirty little hearts
User avatar
alvaro84
Member
 
Posts: 182
Joined: 2007-5-24 @ 05:04
Location: Hungary

Re: List of 486 motherboards to work well with the Pentium Overdrive (POD) in write-back mode

Postby BeginnerGuy » 2017-11-19 @ 18:41

alvaro84 wrote:Is there a good and sure way to quickly test the cache in WB/WT mode? Or just watch out random instability?


There is a program out there, I'll hunt for it later and see if it exists on the internet. I remember this topic popping up on usenet regularly and there were a few homebrew apps being passed around that could tell you if WB was working.

Browsing the old topics on google groups would be a good start.
Sup. I like computers. Are you a computer?
User avatar
BeginnerGuy
Oldbie
 
Posts: 614
Joined: 2016-12-19 @ 08:32
Location: North Carolina, US

Re: List of 486 motherboards to work well with the Pentium Overdrive (POD) in write-back mode

Postby feipoa » 2017-11-20 @ 00:57

Various programs usually will inform you what state the L1 cache is in. The BIOS may or may not mis-report it. Try CHKCPU 16-bit, for example, or cachechk. Perhaps CTCM and CTCM7. I suspect, though, that sometimes the system tries to put the L1 in write-back mode, but the system is just horribly unstable. Try installing Windows 9x, for example, and watch the errors pop up. Also, the Quake benchmark results will offer some insight as to the L1 cache state.
User avatar
feipoa
l33t++
 
Posts: 5514
Joined: 2011-3-07 @ 13:54
Location: Canada

Re: List of 486 motherboards to work well with the Pentium Overdrive (POD) in write-back mode

Postby Anonymous Coward » 2017-11-20 @ 13:51

Here's a fun fact. Did you know that the Intel Mercury chipset, the one for the P60/P66 also doesn't work properly in WB mode? At least Intel issued some kind of statement recommending that all of their vendors run WT mode because the WB mode was defective. Not sure if it affects some, most or all of the motherboards using the Mercury chipset. So, don't feel too bad that WB doesn't work on your POD, because it didn't even work on a proper Pentium.
Will the highways on the internets become more few?
V'Ger XT|Upgraded AT|Ultimate 386|Super VL/EISA 486|SMP VL/EISA Pentium
User avatar
Anonymous Coward
l33t
 
Posts: 2829
Joined: 2008-3-20 @ 05:37
Location: Shandong, China

Re: List of 486 motherboards to work well with the Pentium Overdrive (POD) in write-back mode

Postby amadeus777999 » 2017-11-20 @ 17:28

Anonymous Coward wrote:Here's a fun fact. Did you know that the Intel Mercury chipset, the one for the P60/P66 also doesn't work properly in WB mode? At least Intel issued some kind of statement recommending that all of their vendors run WT mode because the WB mode was defective. Not sure if it affects some, most or all of the motherboards using the Mercury chipset. So, don't feel too bad that WB doesn't work on your POD, because it didn't even work on a proper Pentium.


Very interesting - never heard of this before.
User avatar
amadeus777999
Member
 
Posts: 479
Joined: 2013-7-04 @ 17:04

Re: List of 486 motherboards to work well with the Pentium Overdrive (POD) in write-back mode

Postby feipoa » 2017-11-20 @ 18:51

amadeus777999 wrote:
Anonymous Coward wrote:Here's a fun fact. Did you know that the Intel Mercury chipset, the one for the P60/P66 also doesn't work properly in WB mode? At least Intel issued some kind of statement recommending that all of their vendors run WT mode because the WB mode was defective. Not sure if it affects some, most or all of the motherboards using the Mercury chipset. So, don't feel too bad that WB doesn't work on your POD, because it didn't even work on a proper Pentium.


Very interesting - never heard of this before.

Intel probably preferred it that way!
User avatar
feipoa
l33t++
 
Posts: 5514
Joined: 2011-3-07 @ 13:54
Location: Canada

Re: List of 486 motherboards to work well with the Pentium Overdrive (POD) in write-back mode

Postby feipoa » 2017-11-20 @ 20:10

Nobody else using the POD in their retro systems?
User avatar
feipoa
l33t++
 
Posts: 5514
Joined: 2011-3-07 @ 13:54
Location: Canada

Re: List of 486 motherboards to work well with the Pentium Overdrive (POD) in write-back mode

Postby kixs » 2017-11-20 @ 20:57

I have it on a shelf... like so many other cool hardware. I'm starting to wonder if I'll ever enjoy any of it for more then a 5 minute test run :lol:
My Amibay: SALE | BUY - Updated on 2018-07-17
User avatar
kixs
l33t
 
Posts: 2090
Joined: 2013-1-31 @ 02:08
Location: Slovenia, EU

Re: List of 486 motherboards to work well with the Pentium Overdrive (POD) in write-back mode

Postby amadeus777999 » 2017-11-20 @ 23:34

Never saw the appeal of having a Pentium on a 486 board - weaker bus plus one pipeline deactivated. Latter could be hearsay though.
User avatar
amadeus777999
Member
 
Posts: 479
Joined: 2013-7-04 @ 17:04

Re: List of 486 motherboards to work well with the Pentium Overdrive (POD) in write-back mode

Postby alvaro84 » 2017-11-21 @ 15:15

feipoa wrote:Nobody else using the POD in their retro systems?


I have but not in a pre-built system. I have 4 486 boards though and will check later. In a few weeks, I presume. Sorry :blush:
Shame on us, doomed from the start
May God have mercy on our dirty little hearts
User avatar
alvaro84
Member
 
Posts: 182
Joined: 2007-5-24 @ 05:04
Location: Hungary

Re: List of 486 motherboards to work well with the Pentium Overdrive (POD) in write-back mode

Postby bjwil1991 » 2017-11-21 @ 15:44

It really depends on the motherboards and BIOS manufacturer. I have a Packard Bell Pack-Mate 28 Plus that'll work with Pentium OverDrives, but require an Interposer, but disables L2 cache all the way.
C64, WheelWriter 10 Series II QuietWriter 8, Pack-Mate 28 Plus, K6-2/300, Pavilion N3350, iMac G3 & G4, Socket 370, 2x Inspiron 600m, Athlon 64, Dimension 4550 & E510, ThinkPad R40, Presario C700, ASUS X54C, Raspberry Pi B+, 2B-3B+, Custom FX-6300
User avatar
bjwil1991
Oldbie
 
Posts: 1700
Joined: 2013-8-14 @ 03:10
Location: SE Michigan, USA

Re: List of 486 motherboards to work well with the Pentium Overdrive (POD) in write-back mode

Postby jesolo » 2017-11-21 @ 16:13

feipoa wrote:Nobody else using the POD in their retro systems?

I have a Pentium Overdrive (POD) 83 MHz currently in my Asus PVI-486SP3. Works great in both Write Back & Write Through (or Thru) mode.
I also have a Luckystar LS-486E, which I think I initially tested the POD with and it also worked fine in both Write Back & Write Through mode.
Both motherboards utilise the SIS 496/497 chipsets and were one of the "later" 486 motherboards so, I didn't expect any problems.

I initially had an AMD5x86 133 MHz in by Asus PVI-486SP3 but, after I managed to acquire the POD 83 MHz, this CPU appealed to me more to use in my "high end" 486 system (despite actually being a Pentium based CPU).
Based on my own benchmarks, the POD 83 MHz runs more or less on par with a Pentium 75 MHz.
User avatar
jesolo
Oldbie
 
Posts: 1448
Joined: 2014-6-24 @ 19:04
Location: South Africa

Re: List of 486 motherboards to work well with the Pentium Overdrive (POD) in write-back mode

Postby feipoa » 2017-11-21 @ 19:00

I recall user Vetz running a POD at 100 MHz in his Asus VL/I-486SV2GX4; don't recall if the POD is in WB or WT mode, though. Obviously, the older the motherboard, the more exotic it would be to have the POD working in WB mode.
User avatar
feipoa
l33t++
 
Posts: 5514
Joined: 2011-3-07 @ 13:54
Location: Canada

Re: List of 486 motherboards to work well with the Pentium Overdrive (POD) in write-back mode

Postby dirkmirk » 2017-11-22 @ 00:59

I like the Cyrix 5x86-120 much more than the POD-83, faster bus but weaker FPU is a fair trade off IMO.
dirkmirk
Oldbie
 
Posts: 814
Joined: 2007-5-20 @ 03:00
Location: Australia

Re: List of 486 motherboards to work well with the Pentium Overdrive (POD) in write-back mode

Postby feipoa » 2017-11-22 @ 01:38

The POD only gets interesting to me when its run at 100 MHz.
User avatar
feipoa
l33t++
 
Posts: 5514
Joined: 2011-3-07 @ 13:54
Location: Canada

Re: List of 486 motherboards to work well with the Pentium Overdrive (POD) in write-back mode

Postby BitWrangler » 2017-11-22 @ 01:44

If you've got a LOT of patience, I'll try and remember this thread if one turns up here. A memory just snuck in of handling one with no fan years back, so if it's still around and turns up, I'll rig something and test on whatever boards are handy.

feipoa wrote:The POD only gets interesting to me when its run at 100 MHz.


Really.... The kickass 486 position is held by the AMDs or Cyrixes, and the terrible pentium system crown is taken by the P60 or P75, so it lacks a purpose in life... except maybe the title of "The first CPU intel should have named Celeron." :D
Basement full of ancient PC stuff, starting to go through it. Most recently toyed with DOS era stuff 15 years ago, so memory might be rusty. So what's this BitWrangler guy's deal ??? >>> http://www.vogons.org/viewtopic.php?f=25&t=56382
User avatar
BitWrangler
Member
 
Posts: 432
Joined: 2017-10-11 @ 00:55

Re: List of 486 motherboards to work well with the Pentium Overdrive (POD) in write-back mode

Postby Anonymous Coward » 2017-11-22 @ 02:10

amadeus777999 wrote:Never saw the appeal of having a Pentium on a 486 board - weaker bus plus one pipeline deactivated. Latter could be hearsay though.


In my opinion, the 60 or 66MHz bus on the pre-Triton Pentiums didn't really matter much, because so many wait states had to be added to make the DRAM and 15ns async cache stable. The memory performance of early Pentiums is not really better than a good 486.

If you have a good board that works with L2 cache enabled and L1 in writeback mode, the POD83 is a pretty good upgrade for a socket3 system. The problem of course was that nobody could really use the POD83 as an upgrade for a pre 1996 board, and you would have had to buy a new one to get the full performance. At that point in time you were much better off investing in socket5/7.
Will the highways on the internets become more few?
V'Ger XT|Upgraded AT|Ultimate 386|Super VL/EISA 486|SMP VL/EISA Pentium
User avatar
Anonymous Coward
l33t
 
Posts: 2829
Joined: 2008-3-20 @ 05:37
Location: Shandong, China

Next

Return to General Old Hardware

Who is online

Users browsing this forum: SETBLASTER and 7 guests