Anyone got any rough idea how much impact the onboard chache for 486 machines has?
I am talking about these individual cache chips on the mainboard. What if I remove them alltogether? What impact would I see.
CPU in question is a 486SX 25 Mhz as this seems to be slowest model that most 486 boards take.
There are 16 and 20 MHz models, but most boards don't go that low...
I don't think you have to remove them. You can disable them instead. You can do this by either going to the BIOS set up area, and setting the mobo's cache to Disabled, or you can use a command line utility called ICD.exe (I think that's its name.) If you search the forums, I seem to remember that both me and Malik have benchmarked 486s with and without cache Enabled. You'll find that if you disable a 486's cache, you get a machine that's about as fast as a 386DX-33. So, it's a useful thing to do.
Thats why I gave that 486-40 based machine a new home. It fills the P3 gap almost completely. It also has a turbo button which slows it down in a different way. With a CF card, it is soooo silent too. 😀
wrote:CPU in question is a 486SX 25 Mhz as this seems to be slowest model that most 486 boards take.
Take this with a grain of salt, but I think you can get a 486-40 just as well. The actual speed it runs at is configured on the mobo. As long as you can match the voltage and the multi is 1x, you can throttle a 486-40 to 486-33 or 486-25 as the board permits.
I have not heard that a DX would pose any problem in acting as 386. Have you?
Else try this:
http://cgi.ebay.de/OPTI-386-WB-Main-Board-/270631383665
ICE and ICD of course! I have these tools. Never thought they might work on a 486 😀
UX-3 brilliant idea!
All the slow 486s are 5V I believe and all I need to do is set the "system speed" e.g. 25MHz or 33 MHz or 40 MHz...
I only mentioned SX because it seemed to be available with the lowest clock speeds, but your tip makes a lot more sense 😉
Reason why I would like a 486 is because the board will be a lot newer and have IDE and FDD onboard. Also PCI videocards are easier to find and I guess the BIOS will be more stable...
Slowest SX ever made was an SX-16.
I got one but no motherboard to put it in, 🤣
Maybe it's a low power version for notebooks or other applications?
wrote:Reason why I would like a 486 is because the board will be a lot newer and have IDE and FDD onboard. Also PCI videocards are easier to find and I guess the BIOS will be more stable...
My 486 has no I/O onboard, it needs a controller card. It also has no PCI. You can't flash the bios either. HDD still limits at 500 MB.
Yea the board I am interested in does have support for 8 GB drives.
wrote:wrote:Reason why I would like a 486 is because the board will be a lot newer and have IDE and FDD onboard. Also PCI videocards are easier to find and I guess the BIOS will be more stable...
My 486 has no I/O onboard, it needs a controller card. It also has no PCI. You can't flash the bios either. HDD still limits at 500 MB.
If you have them (and I realize most here use flash cards instead of the old fashioned loud drives, me excluded) there were harddrives made with a jumper that made those controllers see 2 separate drives. One untested one I have is around 1GB and should be jumperable to 2 500MB ones so older BIOS's can still read them
It does turn the HDD smaller, but I have never encountered one that creates two.
Retro PC warning: The things you own end up owning you.
I will look up that harddrive tomorrow and give you the partnumber
Hehe yes I remember these jumpers...
Just a quick question as I don't want to create a new thread.
Pentium cpus like P54C or P55C did they come witha Turbo Button or other options to slow them down? Or do they suffer from the same issue as Pentium IIs and IIIs meaning they end up way to slow once to disable L1 cache...
wrote:Hehe yes I remember these jumpers...
Just a quick question as I don't want to create a new thread.
Pentium cpus like P54C or P55C did they come witha Turbo Button or other options to slow them down? Or do they suffer from the same issue as Pentium IIs and IIIs meaning they end up way to slow once to disable L1 cache...
The turbo button is a motherboard thing, it has nothing to do with the CPU except for it's multipliers, which are set by the motherboard anyway.
I don't know how much of an impact disabling L1 cache would have but my guess would be the impact to be in between that of a 486 and a P3 (kinda obvious answer, but maybe it'll help 😉 )
Well I guess there is only one way of finding out! 😀
wrote:It does turn the HDD smaller, but I have never encountered one that creates two.
Well, I looked in my attic twice and spend around 2 hours looking in google and found nothing.
I can only conclude from this that I must've been wrong.
I know I had a drive which I thought had that option as I recall having set it aside for my future 386.
Seems I was wrong...AGAIN.
I know I can be wrong but I've been wrong about things a lot lately and I hate spreading misinformation or giving people false hopes.
But atleast I am the kind of person who will admit he was wrong the minute he finds out he is wrong though it still bugs me a bit.
When I do find the drive (and if it indeed has this option which atm seems very doubtfull) I'll report back here but until then, consider it a ghost in my memory from back when I was a hardware newb 😜
I do have a P1 SS7 board here with a few CPUs to boot, going from 133 P1 MMX to 500 MHz K6-2, which does cover some ground. I have never benched it w/o cache - I don't know if the bios permits it, maybe with icd. Would be interesting, how aa AMD behaves vs Intel.
Retro PC warning: The things you own end up owning you.
Yea I got my eyes on some Super Socket 7 boards here in Australia!
Any good boards to look for?
The ones I have in my watch list are:
Aopen AX 59 Pro, Iwill XA100 Plus and GB GA-5AX. One has VIA chipset, the others ALI.
Regarding jumpers...
You aren't wrong at all! I believe I had a Maxtor drive and I am sure it also had such a jumper...
Here a couple of pics:
Though I could swear for my drive it was a 500mb cap jumper.
Look, I did not question the existance of such jumpers. I know many a HDD has the ability to conform to the nearest size barrier. But I never saw one, that would then act as two disks instead.
Regarding SS7: I had a lot of SS7 boards about at a time. I basically inherited a companies P1 pool. I tested a few of them for fun, but it seemed that stability with the AGP port was improvable. I then got them all ready for the elementary school my kids were on at the time. I must add that at that time I owned an Baby AT P1-200, based on an Intel FX chipset. The machine was really cool but its build in bios battery was dying. The speed could be switched from 200 to 100 to 50, which would cover a lot of speeds. Dosbox made it obsolete.
My current P1 is an old Packard Bell SS7, which has no AGP slot. I do have a V3 2000 and V3 3000 PCI for it, in benchmarks, the bloody thing is totally CPU limited! So it is stored away, case is used by a P3
wrote:Look, I did not question the existance of such jumpers. I know many a HDD has the ability to conform to the nearest size barrier. But I never saw one, that would then act as two disks instead.
Regarding SS7: I had a lot of SS7 boards about at a time. I basically inherited a companies P1 pool. I tested a few of them for fun, but it seemed that stability with the AGP port was improvable. I then got them all ready for the elementary school my kids were on at the time. I must add that at that time I owned an Baby AT P1-200, based on an Intel FX chipset. The machine was really cool but its build in bios battery was dying. The speed could be switched from 200 to 100 to 50, which would cover a lot of speeds. Dosbox made it obsolete.
My current P1 is an old Packard Bell SS7, which has no AGP slot. I do have a V3 2000 and V3 3000 PCI for it, in benchmarks, the bloody thing is totally CPU limited! So it is stored away, case is used by a P3
ux-3 is right. I knew about the size cap but I thought I had a drive that was able to be jumpered so that fdisk thought there were 2 drives. The drive was 1Gb or slightly under. But since I can't find the drive anyway (I know I got it, must've put it someplace outside of my regular harddrive storage so I wouldn't misplace it, hehe 😜 )it's a moot point now.
Btw, it was YEARS ago that I found that drive and, as I was new to hardware at the time, must've misinterpreted one of the jumpers on that drive.
I guess 500MB will do just fine for a 386 anyway 😜
Another thing ux-3:
I believe I have a couple of the boards you also have. What is important is what chipset it's using. I know of 2 that were used in those PB's, 5598 and 530.
As a matter of fact, both are capable of supporting the K6-3+ with a modded BIOS taken from the unofficial K6+ page 😉
I believe the motherboard is either of these 2:
http://www.bcmcom.com/tech/in5598/IN5598.htm
http://www.bcmcom.com/tech/IN530/IN530.htm
Heres the pages from PB itself:
http://www.uktsupport.co.uk/pb/mb/850.htm
http://www.uktsupport.co.uk/pb/mb/980.htm
If the board you own is one of these 2, personally I think they are ok. One of the better Socket 7 boards. Ofcourse there are even better ones but I tend to like these.
Gotcha!
Please ux-3 don't take it the wrong way if I confuse something 😉 I'm not a spring chicken anymore 😀
