There are three main hardware considerations if you want to make AccuRendefr go like the clappers. Processor speed, amount of memory, and video card OpenGL speed. Other considerations are minor, but included here to give you the information anyway.

AccuRender will run happily on all x86 processors. However, as it makes a great deal of use of the Floating Point Unit (FPU), Intel processors have always been the strongest in this area, but the new Athlon processors are looking even stronger in current benchmarks. However as we have seen no reports of AccuRender speed on an Athlon, we cannot recommend one over the other.

The cache arrangement makes only a minimal difference to AccuRender. This means that Celerons, Pentiums (2 and 3) and Pentium Xeons will run approximately the same speed with similar clock rates.

AccuRender supports as many processors as the operating system will support. This means one under Windows 95/98, two processors under Windows NT 4.0 Workstation and more under NT Server or Windows 2000. Each processor after the first will make AccuRender perform about 80% faster, so a combination of two 300Mhz processors will give approximately the same performance as a 550Mhz unit. Celerons, in their unmodified form, do not work in multi-processor configurations, but certain motherboard manufacturers have taken the opportunity to use PPGA (Socket) Celerons in multi-processor arrangements. These are an extremely cheap and fast solution for AccuRender, but we cannot be sure what the upgrade potential will be.

AccuRender isn't optimised for KNI (Intel’s new instruction set for the Pentium III) so the Pentium III does not make much difference, other than the increased clock rate. Nor is AR3 optimised for AMD’s 3DNOW! instruction set, so there will be no performance gains from that either. However, it is worth noting that AutoCAD 2000 has support for KNI, and newer video cards also take advantage of the new instructions. As yet, we have seen no reports of speed increases for these configurations.

There is no "best configuration" that we can recommend for processors. You must balance the initial cost against future expansion requirements. Naturally, the purchase of a dual processor capable motherboard from the outset will allow much greater expansion. Remember, if you start with one processor and intend to upgrade to two in the future, install NT with the multi-processor kernel from the start.

Models that are more complex require more memory, particularly if you intend to use radiosity and/or a lot of plants in your models. If you run out of physical memory, you processor speeds are not going to matter because Windows will spend most of its time "paging". Buy memory, as much as you can - 128Mb is just about enough, 256Mb is OK, 512Mb is good. 1Gb is great. Make sure you have enough room to expand the memory in the future.

Memory speed (or more importantly, the speed of your "front side bus", usually 66Mhz or 100Mhz) will have only a small impact on performance.

Graphics cards
The graphics card’s main use is for drawing the walkabout window. For this, you need full OpenGL support. This can be found on many "gamers" cards such as the TNT and TNT2 type units. It is noticeably absent from the Voodoo cards (including the Voodoo 3) and until recently the Matrox G200 (There are now Windows 95/98 OpenGL drivers for this card, but the NT drivers still do not fully support it).

Gaming cards, however, have given a number of problems to AccuRender users, particularly, the Diamond range of cards. The Diamond Viper v550 in particular can cause problems from loss of the background image in the walkabout window, to crashing AccuRender completely. Using the nVidia detonator drivers have solved many of these problems, but some still remain. We should add, though, that this card is very popular, and because there are more users, naturally more people are reporting problems.

Full OpenGL support is de-rigour for the high end workstation cards, such as the Elsa range, or those made by 3D Labs. These cards have been used with very good results, although they cost a premium.

The amount of memory in the card doesn't need to be massive - Graphics cards use this for texturing after the first 16Mb or so, and AccuRender doesn't support material mapping in the walkabout window (yet). If you are comparing cards, look for the raw OpenGL speed. This will tell you how good it is for AccuRender.

The graphics card will make no difference to your rendering times, unless you count the short amount of time needed to regenerate the screen during a radiosity calculation.

If you are considering rendering video, you should also opt for a video card which supports hardware video decoding. Usually this will involve a proprietary CODEC, such as MJPEC (Motion JPEG) with which you must encode your animation (see the tip 6). This will mean that your video files will only be playable on this card, although if your card also has a TV out socket, you can easily record your animation to video tape. Some good examples of this type of card are the Matrox G200 Marvel (or Mystique and Rainbow Runner combination) and the ATI All in Wonder 128. Other add-on cards to do this (using an extra PCI slot) are also available.

Hard Drives
SCSI hard drives make little difference to rendering performance in AccuRender. If it's using the hard drive excessively while you’re rendering, you're in trouble because you’ve run out of memory.

You may, though, wish to invest in a large, fast drive if you intend to make many, detailed images or animations. Video files can take up huge amounts of hard drive space and you will need at least triple the file size in order to manipulate the data. It is not uncommon for an AVI file, with video and sound, to reach 500Mb, so several Gigabytes of space will be useful.

Similarly, video requires fast access times to stream the data without skipping frames. SCSI drives will be better for this kind of work, but good IDE drives are catching up.

With the amount of information contained in a complex 3D model, you will undoubtedly need a large monitor capable of high resolutions. 1600x1200 at True Colour (24 or 32 bit) at above 70Hz is considered normal for AutoCAD and AccuRender modelling. Your video card will also need to support high resolutions and colour depth.

Dual processor support was discussed under "processors". Other considerations are the number of spare PCI slots for future expansion, AGP support for video cards, and DIMM slots for memory upgrades.

Other hardware
There is nothing else that will directly affect the speed or performance of AccuRender. However, other peripherals will come in useful. Scanners can be used for background image capture, especially useful for photomontage work. A modem is very important, as you will need to use the internet to download the latest updates from McNeel – not to mention a visit to AccuStudio every day ! Good backup facilities are crucial – remember to back up those material libraries.

rev 06.5.01   ::   For more information visit www.accustudio.com

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