Personal computing discussed

Moderators: Flying Fox, morphine

 
bhtooefr
Silver subscriber
Lord High Gerbil
Topic Author
Posts: 8188
Joined: Mon Feb 16, 2004 11:20 am
Location: Newark, OH
Contact:

VME Broken on AMD Ryzen

Fri May 12, 2017 6:09 am

http://www.os2museum.com/wp/vme-broken-on-amd-ryzen/

This would be of rather minor importance - it's only going to affect 16-bit processes running in V86 mode on a 32-bit OS (or memory manager, JemmEx for FreeDOS being the cited one) - if it weren't for the fact that XP and Server 2003 execute the video BIOS in that manner. Still fairly minor - nobody's running either of those OSes on the Ryzen metal - but could be annoying for someone who needs to run one of them in a VM.

My guess as to how AMD's going to fix it? If they can't fix it properly in microcode, just disable the VME bit in the CPUID. There's only one OS where that presents a problem, Windows 2000, where it assumes VME anyway, and VIA's solution (when they were shipping silicon that didn't support VME) was to distribute a patched NTVDM with the driver package.
Image
 
Chrispy_
Gold subscriber
Maximum Gerbil
Posts: 4099
Joined: Fri Apr 09, 2004 3:49 pm
Location: Europe, most frequently London.

Re: VME Broken on AMD Ryzen

Fri May 12, 2017 8:07 am

Well with the massive cash-rich giants like Intel and Microsoft both refusing to support old OSes, I doubt AMD will have the resources or incentive to burden their new product with obsolete 16-bit legacy software support.

I suspect the solution for 16-bit software is soon going to be emulation rather than running anything natively, and I'd hope Microsoft would step up to that plate. If they don't, perhaps VMware or someone else will.
Congratulations, you've noticed that this year's signature is based on outdated internet memes; CLICK HERE NOW to experience this unforgettable phenomenon. This sentence is just filler and as irrelevant as my signature.
 
Concupiscence
Gerbil Elite
Posts: 518
Joined: Tue Sep 25, 2012 7:58 am
Location: Dallas area, Texas, USA

Re: VME Broken on AMD Ryzen

Fri May 12, 2017 9:03 am

bhtooefr wrote:
http://www.os2museum.com/wp/vme-broken-on-amd-ryzen/

This would be of rather minor importance - it's only going to affect 16-bit processes running in V86 mode on a 32-bit OS (or memory manager, JemmEx for FreeDOS being the cited one) - if it weren't for the fact that XP and Server 2003 execute the video BIOS in that manner. Still fairly minor - nobody's running either of those OSes on the Ryzen metal - but could be annoying for someone who needs to run one of them in a VM.

My guess as to how AMD's going to fix it? If they can't fix it properly in microcode, just disable the VME bit in the CPUID. There's only one OS where that presents a problem, Windows 2000, where it assumes VME anyway, and VIA's solution (when they were shipping silicon that didn't support VME) was to distribute a patched NTVDM with the driver package.


Blech. Looks like I might keep my FX-8320e box around for vintage virtualization needs after all.
Workstation: Ryzen 1700, 16 gigs RAM, GTX 1050 Ti, Win10 Pro x64
HTPC: i3 4170, 8 gigs RAM, Geforce GTX 750 Ti, Windows 8.1 x64
Mac Pro 3,1: Dual Xeon e5462s, 14 gigs RAM, Radeon 2600XT, El Capitan
 
wingless
Gerbil XP
Posts: 386
Joined: Sun Jun 10, 2007 6:38 pm
Location: Houston, TX
Contact:

Re: VME Broken on AMD Ryzen

Fri May 12, 2017 9:13 am

I run a Pentim 200MMX on Win98SE for 16-bit software. Real DOS on real hardware is better.
Intel Core i7 2600K | 16GB DDR3-2133 | ASUS P8Z77-V Pro | Silverstone 750W | ASUS Strix GTX 980 OC | ASUS Xonar DSX/S.M.S.L. M2 USB DAC | Samsung 840 Pro | A bunch of HDDs and a lot of TBs.
 
Concupiscence
Gerbil Elite
Posts: 518
Joined: Tue Sep 25, 2012 7:58 am
Location: Dallas area, Texas, USA

Re: VME Broken on AMD Ryzen

Fri May 12, 2017 9:15 am

wingless wrote:
I run a Pentim 200MMX on Win98SE for 16-bit software. Real DOS on real hardware is better.


At this point sourcing the real hardware's just too much of a hassle. And I say this as someone who's got a 6 MB Canopus Pure3D sitting in his parts bin.
Workstation: Ryzen 1700, 16 gigs RAM, GTX 1050 Ti, Win10 Pro x64
HTPC: i3 4170, 8 gigs RAM, Geforce GTX 750 Ti, Windows 8.1 x64
Mac Pro 3,1: Dual Xeon e5462s, 14 gigs RAM, Radeon 2600XT, El Capitan
 
Flying Fox
Gerbil God
Posts: 25418
Joined: Mon May 24, 2004 2:19 am
Contact:

Re: VME Broken on AMD Ryzen

Fri May 12, 2017 9:23 am

Concupiscence wrote:
wingless wrote:
I run a Pentim 200MMX on Win98SE for 16-bit software. Real DOS on real hardware is better.


At this point sourcing the real hardware's just too much of a hassle. And I say this as someone who's got a 6 MB Canopus Pure3D sitting in his parts bin.

Just ask Starfalcon? :P :lol:
The Model M is not for the faint of heart. You either like them or hate them.

Gerbils unite! Fold for UnitedGerbilNation, team 2630.
 
Concupiscence
Gerbil Elite
Posts: 518
Joined: Tue Sep 25, 2012 7:58 am
Location: Dallas area, Texas, USA

Re: VME Broken on AMD Ryzen

Fri May 12, 2017 10:29 am

Flying Fox wrote:
Concupiscence wrote:
wingless wrote:
I run a Pentim 200MMX on Win98SE for 16-bit software. Real DOS on real hardware is better.


At this point sourcing the real hardware's just too much of a hassle. And I say this as someone who's got a 6 MB Canopus Pure3D sitting in his parts bin.

Just ask Starfalcon? :P :lol:


...hmm.

I mean, I think DOSbox and a virtual machine will probably suit my needs better - and god knows if performance is a consideration, even my FX-8320e will stomp a native-era hardware solution flat - but there's something fun about a 486 running in 2017. Though I appreciate the heads up, I think I'll politely decline.
Workstation: Ryzen 1700, 16 gigs RAM, GTX 1050 Ti, Win10 Pro x64
HTPC: i3 4170, 8 gigs RAM, Geforce GTX 750 Ti, Windows 8.1 x64
Mac Pro 3,1: Dual Xeon e5462s, 14 gigs RAM, Radeon 2600XT, El Capitan
 
meerkt
Gerbil Elite
Posts: 809
Joined: Sun Aug 25, 2013 2:55 am

Re: VME Broken on AMD Ryzen

Fri May 12, 2017 12:30 pm

Chrispy_ wrote:
I doubt AMD will have the resources or incentive to burden their new product with obsolete 16-bit legacy software support.

But it's officially part of x86. My guess is that they'll fix it in a future core stepping.

wingless wrote:
I run a Pentim 200MMX on Win98SE for 16-bit software. Real DOS on real hardware is better.

Kinda weak for 98SE, no?

Concupiscence wrote:
And I say this as someone who's got a 6 MB Canopus Pure3D sitting in his parts bin.
Call it plainly. Voodoo 1! :)
 
bhtooefr
Silver subscriber
Lord High Gerbil
Topic Author
Posts: 8188
Joined: Mon Feb 16, 2004 11:20 am
Location: Newark, OH
Contact:

Re: VME Broken on AMD Ryzen

Fri May 12, 2017 2:51 pm

Chrispy_ wrote:
Well with the massive cash-rich giants like Intel and Microsoft both refusing to support old OSes, I doubt AMD will have the resources or incentive to burden their new product with obsolete 16-bit legacy software support.

I suspect the solution for 16-bit software is soon going to be emulation rather than running anything natively, and I'd hope Microsoft would step up to that plate. If they don't, perhaps VMware or someone else will.

Although AMD's actually been pitching legacy support as a big advantage of their embedded platform as of late.

Of the x86 vendors selling anything reasonably modern (and by "reasonably modern", I mean at least Pentium Pro class - and this list consists of Intel, AMD, and VIA), AMD is the only one that supports ISA DMA, as one example.

And, it doesn't just affect running 16-bit userland on a 32-bit OS, it also affects booting XP and Server 2003, both natively and in virtualization. (Yes, I know, you shouldn't be running XP in 2017, but a lot of people still do. And, when Zen makes it down to the G-Series SKUs, that'll be a big issue.)

Like I said, the best bet may well be to simply disable the VME flag - it only breaks Windows 2000, and embedded applications that need NT 5 almost always work on XP or Server 2003. Every other known OS that uses VME has an alternate codepath, as far as I'm aware, for running 16-bit software.
Image
 
Chrispy_
Gold subscriber
Maximum Gerbil
Posts: 4099
Joined: Fri Apr 09, 2004 3:49 pm
Location: Europe, most frequently London.

Re: VME Broken on AMD Ryzen

Fri May 12, 2017 3:04 pm

Ryzen may be "x86 compatible" but both AMD and Intel have culled older OSes from their support list, Vista was the first OS that ditched V86 mode entirely and Ryzen is officially a Windows10-only product.

Like you say, a simple microcode change would stop it from happening. Whether AMD are even going to bother is another matter. I mean who would buy a multicore 64-bit processor to run a 32-bit OS emulating 16-bit via VM?!
Congratulations, you've noticed that this year's signature is based on outdated internet memes; CLICK HERE NOW to experience this unforgettable phenomenon. This sentence is just filler and as irrelevant as my signature.
 
whm1974
Gerbil Elder
Posts: 5462
Joined: Fri Dec 05, 2014 5:29 am

Re: VME Broken on AMD Ryzen

Fri May 12, 2017 3:46 pm

Chrispy_ wrote:
Ryzen may be "x86 compatible" but both AMD and Intel have culled older OSes from their support list, Vista was the first OS that ditched V86 mode entirely and Ryzen is officially a Windows10-only product.

Like you say, a simple microcode change would stop it from happening. Whether AMD are even going to bother is another matter. I mean who would buy a multicore 64-bit processor to run a 32-bit OS emulating 16-bit via VM?!

So this "issue" is overblown then?
 
meerkt
Gerbil Elite
Posts: 809
Joined: Sun Aug 25, 2013 2:55 am

Re: VME Broken on AMD Ryzen

Fri May 12, 2017 5:39 pm

Chrispy_ wrote:
Ryzen is officially a Windows10-only product.
Where did AMD say that?
 
bhtooefr
Silver subscriber
Lord High Gerbil
Topic Author
Posts: 8188
Joined: Mon Feb 16, 2004 11:20 am
Location: Newark, OH
Contact:

Re: VME Broken on AMD Ryzen

Fri May 12, 2017 5:48 pm

Chrispy_ wrote:
Ryzen may be "x86 compatible" but both AMD and Intel have culled older OSes from their support list, Vista was the first OS that ditched V86 mode entirely and Ryzen is officially a Windows10-only product.

Actually, XP x64 and Server 2003 x64 did that before Vista. And, 32-bit versions of Vista, 7, 8, 8.1, and 10 (all builds) still have NTVDM and use V86 mode, and I've got NTVDM installed on my one 32-bit Windows 10 device.

Chrispy_ wrote:
Like you say, a simple microcode change would stop it from happening. Whether AMD are even going to bother is another matter. I mean who would buy a multicore 64-bit processor to run a 32-bit OS emulating 16-bit via VM?!

While I don't think the current Ryzen SKUs will be used to run 32-bit Windows natively - they're aimed pretty firmly at enthusiasts that would be running 64-bit Windows anyway - I could easily see it being done with lower-end SKUs, or future embedded SKUs. However, I could also see 32-bit Windows being run in a VM, and that's where you could run into trouble pretty quickly - both for running 16-bit software in that VM (the niche application), and for booting 32-bit XP and Server 2003 (which use VME if it's available for executing the 16-bit video BIOS during boot).

That problem of booting XP or Server 2003 in a VM is really the biggest problem with this - actually running 16-bit user code from within a 32-bit OS (native or guest) isn't that likely in 2017 in most applications of a Ryzen system. But, a quick and dirty fix for both of those cases would be as trivial as modifying CPUID to not advertise VME - even if you take a 10% performance hit, for 16-bit code on Ryzen, you're probably still I/O bound.

As an aside, the author of the original article has suggested that it may be possible to do a proper fix in microcode, as well.
Image
 
Chrispy_
Gold subscriber
Maximum Gerbil
Posts: 4099
Joined: Fri Apr 09, 2004 3:49 pm
Location: Europe, most frequently London.

Re: VME Broken on AMD Ryzen

Fri May 12, 2017 6:30 pm

bhtooefr wrote:
Actually, XP x64 and Server 2003 x64 did that before Vista

Good point. I'd forgotten about XP64 and it's server equivalent, just because they were too early and people who tried them quickly discovered that all kinds of important hardware drivers hadn't been written yet. By the time enough common 64-bit drivers were ready for mainstream consumer use, Vista already had a bad rep and Microsoft were hastily polishing W7 to try and right their wrong :)


meerkt wrote:
Chrispy_ wrote:
Ryzen is officially a Windows10-only product.
Where did AMD say that?

I don't know if this is still the case, but I remember reading about this a lot....
Congratulations, you've noticed that this year's signature is based on outdated internet memes; CLICK HERE NOW to experience this unforgettable phenomenon. This sentence is just filler and as irrelevant as my signature.
 
meerkt
Gerbil Elite
Posts: 809
Joined: Sun Aug 25, 2013 2:55 am

Re: VME Broken on AMD Ryzen

Fri May 12, 2017 7:26 pm

Contradictions from AMD.

On one hand, this may suggest support (though I guess what's actually installed could vary based on the OS):
AMD Chipset Drivers 192 MB 17.10 4/28/2017

Description:
Supports Windows 10/8.1/7 (32 & 64-bit)

Package Includes:
AMD Chipset Drivers
AMD Ryzen™ Balanced Power Plan


On the other hand, here an AMD guy says it's "exclusively designed for Win10" (so no Win8 either?):
https://community.amd.com/community/gam ... -available
 
fullbodydenim
Gerbil
Posts: 18
Joined: Sun May 10, 2015 12:01 am

Re: VME Broken on AMD Ryzen

Fri May 12, 2017 10:51 pm

AMD Ryzen has chipset driver support for Windows 7, 8, 8.1 and 10. There are articles describing how to get it installed on all of these OS's. The problem is Microsoft is only officially supporting it and Intel Kaby Lake on Windows 10. So you might get short-changed on some updates if you use the older OS.
 
bhtooefr
Silver subscriber
Lord High Gerbil
Topic Author
Posts: 8188
Joined: Mon Feb 16, 2004 11:20 am
Location: Newark, OH
Contact:

Re: VME Broken on AMD Ryzen

Sat May 13, 2017 7:28 am

That's AMD's full chipset driver package, though, for all platforms. That doesn't say anything for what Ryzen supports.

And, Ryzen isn't compatible with Windows 8.1 either - Microsoft made the call that 8.1 won't get Kaby Lake, Bristol Ridge, or Ryzen support, even though it's in mainstream support.
Image
 
derFunkenstein
Gold subscriber
Gerbil God
Posts: 23835
Joined: Fri Feb 21, 2003 9:13 pm
Location: Comin' to you directly from the Mothership

Re: VME Broken on AMD Ryzen

Mon May 15, 2017 9:16 am

meerkt wrote:
Chrispy_ wrote:
Ryzen is officially a Windows10-only product.
Where did AMD say that?

Microsoft said it when they started blocking updates on Windows 7 and 8.1.

http://techreport.com/news/31741/update ... ow-blocked
I do not understand what I do. For what I want to do I do not do, but what I hate I do.
 
meerkt
Gerbil Elite
Posts: 809
Joined: Sun Aug 25, 2013 2:55 am

Re: VME Broken on AMD Ryzen

Mon May 15, 2017 9:23 am

Yeah, but AMD can do whatever they want regardless of Microsoft's decisions. Windows is still open enough. For now.
 
derFunkenstein
Gold subscriber
Gerbil God
Posts: 23835
Joined: Fri Feb 21, 2003 9:13 pm
Location: Comin' to you directly from the Mothership

Re: VME Broken on AMD Ryzen

Mon May 15, 2017 10:21 am

That's the least convincing argument ever. Unless AMD is going to repackage Windows updates and distribute them for Ryzen systems, Windows 7 and 8.1 are dead OSes on Ryzen. Running unpatched systems is a horrible idea.

(Edit) case in point: viewtopic.php?p=1350520#p1350521
I do not understand what I do. For what I want to do I do not do, but what I hate I do.
 
meerkt
Gerbil Elite
Posts: 809
Joined: Sun Aug 25, 2013 2:55 am

Re: VME Broken on AMD Ryzen

Mon May 15, 2017 10:55 am

I'm talking about driver/whatever support for CPU-specific features in terms of power modes or thread scheduling.
 
just brew it!
Gold subscriber
Administrator
Posts: 49702
Joined: Tue Aug 20, 2002 10:51 pm
Location: Somewhere, having a beer

Re: VME Broken on AMD Ryzen

Thu May 18, 2017 9:06 am

For most use cases (i.e. all the ones that involve being connected to the Internet) that's kind of moot if you can't get OS updates.
Nostalgia isn't what it used to be.
 
ronch
Graphmaster Gerbil
Posts: 1095
Joined: Mon Apr 06, 2009 7:55 am

Re: VME Broken on AMD Ryzen

Mon May 29, 2017 12:41 am

So could this prevent running old DOS games under DOSBox? I'm still a big fan of old DOS games and those are pretty much 16-bit. Who knows, some of them may even be 8-bit like some really old titles like Dragonworld (1984).
NEC V20 > AMD Am386DX-40 > AMD Am486DX2-66 > Intel Pentium-200 > Cyrix 6x86MX-PR233 > AMD K6-2/450 > AMD Athlon 800 > Intel Pentium 4 2.8C > AMD Athlon 64 X2 4800 > AMD Phenom II X3 720 > AMD FX-8350 > RYZEN?
 
ptsant
Gerbil Team Leader
Posts: 259
Joined: Mon Oct 05, 2009 12:45 pm

Re: VME Broken on AMD Ryzen

Mon May 29, 2017 3:11 am

bhtooefr wrote:
http://www.os2museum.com/wp/vme-broken-on-amd-ryzen/

This would be of rather minor importance - it's only going to affect 16-bit processes running in V86 mode on a 32-bit OS (or memory manager, JemmEx for FreeDOS being the cited one) - if it weren't for the fact that XP and Server 2003 execute the video BIOS in that manner. Still fairly minor - nobody's running either of those OSes on the Ryzen metal - but could be annoying for someone who needs to run one of them in a VM.

My guess as to how AMD's going to fix it? If they can't fix it properly in microcode, just disable the VME bit in the CPUID. There's only one OS where that presents a problem, Windows 2000, where it assumes VME anyway, and VIA's solution (when they were shipping silicon that didn't support VME) was to distribute a patched NTVDM with the driver package.


The problem lies with the INT instruction, under the conditions named above. I suspect that this is typically an instruction written in microcode. In that case it can and will be fixed.
Image
 
ptsant
Gerbil Team Leader
Posts: 259
Joined: Mon Oct 05, 2009 12:45 pm

Re: VME Broken on AMD Ryzen

Mon May 29, 2017 3:13 am

ronch wrote:
So could this prevent running old DOS games under DOSBox? I'm still a big fan of old DOS games and those are pretty much 16-bit. Who knows, some of them may even be 8-bit like some really old titles like Dragonworld (1984).


DOSbox is not a virtual machine. In addition, if you are running in 64-bit mode, the bug does not occur.
Image
 
wingless
Gerbil XP
Posts: 386
Joined: Sun Jun 10, 2007 6:38 pm
Location: Houston, TX
Contact:

Re: VME Broken on AMD Ryzen

Thu Jun 01, 2017 10:27 am

meerkt wrote:
Chrispy_ wrote:
I doubt AMD will have the resources or incentive to burden their new product with obsolete 16-bit legacy software support.

But it's officially part of x86. My guess is that they'll fix it in a future core stepping.

wingless wrote:
I run a Pentim 200MMX on Win98SE for 16-bit software. Real DOS on real hardware is better.

Kinda weak for 98SE, no?

Concupiscence wrote:
And I say this as someone who's got a 6 MB Canopus Pure3D sitting in his parts bin.
Call it plainly. Voodoo 1! :)


I had a Pentium 200MMX in 1997 that we upgraded to 98SE in 1998. It had 48MB of RAM back then. Now I run it with 96MB and an CF hard drive that maxes out the IDE bus so It's plenty fast for what I use it for.

For mid to late '90s DOS gaming it's more than adequate.
Intel Core i7 2600K | 16GB DDR3-2133 | ASUS P8Z77-V Pro | Silverstone 750W | ASUS Strix GTX 980 OC | ASUS Xonar DSX/S.M.S.L. M2 USB DAC | Samsung 840 Pro | A bunch of HDDs and a lot of TBs.
 
meerkt
Gerbil Elite
Posts: 809
Joined: Sun Aug 25, 2013 2:55 am

Re: VME Broken on AMD Ryzen

Thu Jun 01, 2017 12:17 pm

wingless wrote:
For mid to late '90s DOS gaming it's more than adequate.

More speed can't hurt (and memory for Win98 uses), and I don't think it would be any less compatible.
I recall Diablo 1 had super long load times on a Pentium 90. :) MMX 200 would certainly be quicker, but a Pentium III even more.

ronch wrote:
I'm still a big fan of old DOS games and those are pretty much 16-bit. Who knows, some of them may even be 8-bit like some really old titles like Dragonworld (1984).
I don't think DOS ran on i8080? IBM PC started with 16-bit.
Last edited by meerkt on Thu Jun 01, 2017 12:22 pm, edited 1 time in total.
 
meerkt
Gerbil Elite
Posts: 809
Joined: Sun Aug 25, 2013 2:55 am

Re: VME Broken on AMD Ryzen

Thu Jun 01, 2017 12:21 pm

<del me?>
 
bhtooefr
Silver subscriber
Lord High Gerbil
Topic Author
Posts: 8188
Joined: Mon Feb 16, 2004 11:20 am
Location: Newark, OH
Contact:

Re: VME Broken on AMD Ryzen

Sun Jun 11, 2017 3:44 pm

And AGESA 1.0.0.6 includes a microcode update to patch this issue, apparently: http://www.os2museum.com/wp/vme-fixed-on-amd-ryzen/
Image

Who is online

Users browsing this forum: No registered users and 1 guest