NVDI

Wait a minute, not so fast...

NVDI is a program I have used since the mid 90s, and one of those programs that when you start using, you wonder how you ever did without it. In fact, I would go as far as saying it is one of the most valuable pieces of software for the TOS series of computers. In recent times however, I have wondered if I could 'upgrade' my copy of NVDI 3.02 to eek a little more performance out of my TOS based machines. Yet a surprise when benching my upgraded STFM has subsequently led me to pen this article.

Developed by Behne and Behne and released in 1990, this N(ew) VDI completely replaces the Virtual Device Interface from Atari with faster display routines. Beginning life as a software accelerator, which however also included its own faster version of Atari's Graphic Design Operating System (GDOS). GDOS being Atari's software based part of TOS which allows the usage of Bitstream 'GDOS' fonts and printer drivers, allowing for a more diverse array of fonts for use in Word Processing and Desktop Publishing applications for example, outputting to a wider selection of printers than those produced by Atari. For reference, SpeedoGDOS came later, and again was Atari's answer to speeding up GDOS, initially offering the ability to use 'Speedo' fonts as well as GDOS fonts.

NVDI 2.5x

Enter NVDI 2.5 in 1993, this was a significant update as this was the fastest NVDI software accelerator to date, as you would imagine, and offered Atari Falcon compatibility meaning support for all TOS machines.

Highlights

Compatibility with all TOS machines
Support for an array of printers
Support for GDOS fonts

To get a sense of how good NVDI 2.5 is as a software accelerator, I compared it to my STFM running in High resolution with 4MB of RAM under TOS 2.06.

The referenced GEMBench STFM test was performed in Medium resolution under TOS 1.04, so the figures will not be at 100%, with benchmarks showing my STFM running in High resolution, and against TOS 2.06 without NVDI. I could have re-baselined to start at 100%, however the important figures are of course the actual timings.

Baseline

Display: 141%

CPU: 99%

Average: 118%

Now to see how NVDI 2.5, or rather NVDI 2.51 improves things, again using the same referenced STFM test, and again running under TOS 2.06 and with 4MB.

That's quite an improvement running at 8MHz, improving those GEM, VDI and BLiTTing routines by a significant margin.

Baseline NVDI 2.51

Display: 141% 508%

CPU: 99% 99%

Average: 118% 224%

NVDI 3.0x

NVDI 3.0 was released in 1994, and was a complete re-write of NVDI, requires less memory to run, and introduced the ability to use Speedo fonts, as well as TrueType fonts, with separate ET4000 graphic card support. Version 3.02 was the version I purchased in 1995. It was at this time I took the decision not to go the PC route, and instead upgrade my STFM with a System Solutions 850MB MiniS SCSI hard drive, a TOS 2.06 switcher, OverScan, a Canon BJ10SX printer, and to purchase both Papyrus Gold and Atari Works. A significant outlay for the time, but I was obsessed with all things ST. This allowed me to do my college work on my ST, which I used as my main computer until 2003. Without NVDI, undergoing my college work on my ST would have been severely hampered, without that speed, usage of TrueType fonts and printer drivers.

Highlights

Compatibility with all TOS machines
Support for more printers
Support for GDOS, Speedo and TrueType fonts
Separate ET4000 graphic card support
Less memory 'intensive'

However, as good as all of those features are, how does NVDI 3.02 stack up against NVDI 2.51?

That's interesting, NVDI 3.02 is marginally slower, so if the handling of fonts are not important to you, or rather in this day and age you don't care, you may be better off with NVDI 2.5 for out and out software acceleration, although the difference is marginal. However for me, the usage of TrueType fonts is a very nice feature, including those Speedo fonts, and more significantly the fact that NVDI 3.02 uses less memory, makes NVDI 3.02 my personal favourite, at least for now.

Baseline NVDI 2.51 NVDI 3.02

Display: 141% 508% 507%

CPU: 99% 99% 99%

Average: 118% 224% 224%

NVDI 4.xx

NVDI 4.0 came long in 1996, and again enhanced NVDIs capabilities. It again improved printing to a wider choice of printer, and included better support for colour printing over NVDI 3.0x, and enhanced TrueType font handling. It was possible to utilise Postscript fonts from an optional new module, and similarly had separate ET4000 graphic card support.

Highlights

Compatibility with all TOS machines
Even more support for printers
Support for GDOS, Speedo and TrueType fonts, with enhancements to TrueType font handling
Optional module for handling Postscript fonts
Separate ET4000 graphic card support
A little more memory intensive

With these enhancements to NVDI 4, how does NVDI 4.11 perform against its older siblings as a software accelerator?

There seems to be a trend! With the enhancements that later NVDI versions offer, they appear to get marginally slower as a software accelerator, and with NVDI 4.11, it may not be a big leap forward as an upgrade, certainly with it using a little more memory.

Baseline NVDI 2.51 NVDI 3.02 NVDI 4.11

Display: 141% 508% 507% 506%

CPU: 99% 99% 99% 99%

Average: 118% 224% 224% 224%

NVDI 5.0x

Lastly we get to NVDI 5.0 released in 1999, with the final version of NVDI ending at NVDI 5.03. NVDI 5.0 offers one consolidated application for Atari, Mac and PC, and during installation recognises which platform is under use. During boot, it no longer lists fonts being loaded, which for me personally is a downgrade, but that's just me, now integrates Postscript font handling as standard, extends and consolidates graphic card support, and of course further extends printer support.

Highlights

Compatibility with all TOS machines
Consolidated cross platform package for Atari, Mac and PC
Support for yet more printers
Support for GDOS, Speedo, TrueType and now Postscript fonts as standard
Consolidated graphic card support for more graphics cards
Again more memory intensive, quite substantially

Not bad at all, however other than the handling of Postscript fonts and graphic card support, is it any better as a software accelerator than its predecessors?

There is the answer, surprisingly with NVDI 5.03, it is a little slower than its predecessors running at 8MHz under TOS 2.06 on an STFM in High resolution. Where NVDI 5.03 may not give you the acceleration you are after over earlier NVDI versions, you may find the use of Postscript fonts, extra printer drivers, graphic card support, as well as other small-ish enhancements of benefit.

Baseline NVDI 2.51 NVDI 3.02 NVDI 4.11 NVDI 5.03

Display: 141% 508% 507% 506% 457%

CPU: 99% 99% 99% 99% 99%

Average: 118% 224% 224% 224% 213%

Conclusion

So it seems fair to conclude, the best NVDI may not necessarily be the last version, NVDI 5.03. However it largely depends on your needs, as if the use of Postscript fonts is useful to you for example, or specific graphic card support, then it may very well be the version for you, despite it being the slowest as a software accelerator, especially at 8MHz and without a BLiTTER. Things do improve at 16MHz for NVDI 5.03, and the further up the food chain you get, as there is less difference on a Falcon for example, but I still found 5.03 to be a little slower, and in fact has the largest footprint of all versions.

As a side note, with the Falcon you cannot switch the BLiTTER on and off with ease under TOS 4.04, however NVDI 5.03 does cater for this, meaning it does not automatically force the BLiTTER off, something earlier NVDI versions cannot do on the Falcon. For STEs with a BLiTTER this is not a problem, as TOS takes care of this, but TOS 4.04 on the Falcon does not. XBoot has the option to turn the BLiTTER on and off, but doesn't make a difference under TOS 4.04 using earlier NVDIs. If you wish to take advantage of using the BLiTTER on the Falcon with NVDI, then use NVDI 5.03, as both can co-exist with some small gains combined. If like me however, you want to take advantage of the speed gains earlier versions of NVDI give you over 5.03, alongside the BLiTTER on the Falcon, then you can use Mikro's FGeneral CPX, a patched version of the Falcon's General CPX, which allows you to turn the BLiTTER on and off, as well as the cache. Usefully the BLiTTER can be made to stay on using earlier NVDI versions upon booting the Falcon using this CPX.

So there we have it! If software acceleration is paramount, and graphic card support or font handling et al are not, you may be better off sticking to NVDI 2.51. For me however, the best compromise is NVDI 3.02. It is marginally slower than NVDI 2.51, really marginal, it can handle Speedo and TrueType fonts, and uses less memory under usage. All things said, the choice again is subjective, and depends what may be useful to you, as there are arguments for and against all of the versions under test.