How picky is NT 4.0 with CPUs?

[Zare]

Which is exactly what people have done.

I know of a dual-CPU system which told NTLDR that the machine only has one CPU. A custom NT kernel driver then brought up the second CPU and ran a bespoke PLC real-time emulation for real-time control of semiconductor equipment. Some oscilloscope vendors are known to have used very special graphics drivers on their NT-based offerings to allow the FPGA circuitry to directly draw into the framebuffer and bypass the OS latency.

Both solutions do not survive OS upgrades, but they combine hard real-time guarantees with the freedom of using cheap PC-style hardware, existing file systems and development knowledge and tools.

I'm not surprised to read this, because people have done everything. I think the end of your post is most important - "development knowledge and tools" because they bent that NT over its rear to achieve the goal. I've seen the most inventive and eye-brow raising things from Microsoft developers that just dogmatically said we'll use Windows and do whatever is necessary regardless of OS standing in the way.

I’m sure plenty of the older folks here remember hearing the stories of, say, Novell Netware servers that ran for 16 years straight and were only shut off because the whine from their worn-out disk bearings became intolerable. (Or the even juicier ones about insert-vendor-here servers that were so quietly reliable nobody noticed for years when the closet they were in got walled off.) There is indeed nothing particularly impressive about a computer sitting in one place running the same software for years, particularly if it’s just something like serving files.

Yeah the age old story of Unix server responding to pings but noone knows where it's at.

 

[czunit]

Also keep in mind that in NT 4 the hardware concept was abstracted with HALs (Hardware Abstraction Layers). There was a standard PC HAL (the default) and then special ones for things like the 3550 (multi bus multi processor), and the HAL for the SystemPro (with master/slave CPU concepts, like a VAx 782). I believe there was also one for a Everex Step/MP series as well.

The default HAL was pretty stupid, so as long as the CPU supports the 486 cache register (I don't think it ran on a straight 386) it should work.

 

[rmay635703]

I've still got it (NT 4.0 server) installed on a 6x86 system. Resides on a CF card.

Interesting I remember vaguely a major outlet claiming the 1st Gen 6x86 chips would lock up under NT3.51

Looking back I just see poor performance mentioned

All Bananas

Problems with the Cyrix 6x86's cache under Windows NT have forced Microsoft to more or less high-handedly reconfigure the processor

www.tomshardware.com

CYRIX WORKS TO IMPROVE 6X86 P200 CHIP FOR WINDOWS NT - Tech Monitor

Cyrix Corp is working on a software patch for its 6x86 P200+ chip that will improve its performance when running Windows NT Workstation 4.0. PC Week reports.

techmonitor.ai

 

[czunit]

I'd have to look in my old Lotus Notes/CC:Mail stuff but I think we got NT 4.0 prerelease running on a 386/33. At some point everyone said "Nope, gotta have Intel's 486 cache commands" and it all went down.