Slowmotion

S l o w m o

What is Slowmo??

When you push the 'O' key during a replay or when you are playing GP2, the game will show you a percentage value that indicates how bussy your processor is. This value is called Processor Occupancy (PO) and ranges from 0 to 100% .... and HIGHER.

Basically, a value less than 100% means that you are driving in "realtime": your processor is fast enough to calculate the desired framerate with the selected graphical options(objects around the track, textures, smoke..). So if you drive a lap in 1m30 (simulated time), you will have been driving (close to) 1m30 in reality also. When you would have a constant PO-value of 200% during driving, the simulated time would still be 1m30, but if you watch your clock on your wrist, you'll notice that you drove around 3min in reality! You drove in slowmotion! (clearly recognisable in the slowdown of the action on screen) No, this has nothing to do with Einstein's Theory of Relativity: your processor simply tries to calculate all the frames, but since it is not powerful enough it needs twice as much time as desired.

Note that it does not really work like that the other way round: if your processor is so powerful that it has only 50% occupancy, you will not play faster than realtime. Also note that the "watch your clock"-experiment above is a theoretical example.

Why is this important?

When you set the framerate and/or graphics detail to a level that your computer cannot deliver in realtime, the game slows down and gives you more time to react. For example it becomes much easier to read your speed in corners. It's clear that this is against the spirit of hotlapping! Ultimately, hotlapping is all about testing your reactions...in realtime. Driving in slow-motion gives you an advantage over other people. Tests in practice have shown that people can be upto 0.8 seconds faster on a track like Adelaide, only by forcing a PO of 160-170 instead of under 100!! It is very difficult, even impossible to spot this on the basis of a replay. When you watch a replay of someone elses lap on your computer, the occupancy values reflect the occupancy of your own processor. So it does not give information about the PO when he was driving on his system. The only indications are things like speed of gearchange or other actions that seem to be executed supernaturally fast when replayed in realtime.

Slowmo and HOF2.5

If you take a look at the rules, certainly if you carefully read the Declaration of Intent, you'll understand that HOF2.5 is absolutely anti-slowmo...Slowmotion driving is totally against the very spirit of hotlap leagues and no less than a disgrace. The previous edition of HOF2.5 went down because of slowmo, since it was undetectable at the time.

Thanks to Gp2lap, we now have the power to ban slowmo. Gp2lap monitors the real PO during driving, and HOF2lap enables to check it out. It was decided that hotlaps for HOF2.5 will only be accepted if two conditions are met:

1. the AVERAGE value of the PO during the hotlap should be AT MOST 90%

2. during the lap, you should have been AT MOST 5 seconds above 100%

To make sure that your PO will be legal, you should drive some testlaps before you start trying seriously. This means: drive some laps around that particular track and with the framerate and graphics detail that you plan to use. GP2LAP will then inform you of the average and maximum PO, and the number of seconds that you were over 100%. Outside the game, you can use HOF2lap to check these things. Also always drive from DOS: when running from Win95/98, you can experience short bursts of processor occupancy caused by disk activity!

Some tips to get lower PO

I know that people with lower-spec machines could have troubles with trying to stay under the mandatory PO-figures during a lap. Certainly in SVGA. That's also why some absolutely stunning new tracks aren't used (yet) in HOF2.5: very few people would be able to run them properly!

Here are some tips to get that PO-figure down:

1. for a good approximation, always set the desired framerate about 2 frames per second lower than the framerate that GP2 "recommends". GP2 is typically too optimistic with this estimate, and you end up with slightly sluggish gameplay.

2. run in DOS instead of Windows95: I experienced a speed difference equivalent to something like 1.5-2 fps. For HOF2.5, it is virtually necessary to run from DOS because in Win95/98 you run a high risk of crashing the game when saving hotlaps!!!

3. you don't need any details, let alone textures in the mirrors when hotlapping, and not much else either! We are not here to admire the landscape! So turn them off and only leave the most essential ones on.

4. use one of those bigger cockpit pictures that you can download from the Net. A bigger cockpit (maybe even combined with smaller mirrors) leaves a smaller part of the screen to be updated, and as such it makes the game slightly faster.

Here's a small investigation concerning PO: driving identical laps with a big cockpit and a small cockpit, both under DOS and Windows. Here are the PO-figures reported by GP2lap:

Cockpit	Average/Max PO under DOS	Average/Max PO under Win95
	88/116	90/125
	86/116	88/125

The cockpit doesn't have too much influence, but Windows considerably raises the maximum PO. Combine this with the occasional PO-peaks, and the advice definitely is: drive under DOS for HOF2.5!