Prefetch discussion

[terrypin]

Just started browsing this forum. Why are threads like "Prefetch option should be removed" Locked please, when the last post was only 2 days ago?

 

I was going to post as follows:

 

I see 'Mr G' mentioned; presumably the author of CCleaner? Does he read these threads? I don't see any response to this apparently valid challenge over the detrimental nature of deleteing prefetch data. Nor to the issue I was reading earlier about the bug (still unfixed?) for Firefox users.

 

--

Terry, West Sussex, UK

[Tarun]

The threads were locked to stop arguments from persisting after warnings were issued.

 

The validity of the accusations were not enough to make it a bug. The point of the matter was that nanoseconds were all that really changed, along with the space of the Prefetch folder contents.

[fredvries]

I understand the decision to close the discussion because all that could be said was said.

 

But the whole point is that CCleaner is a cleaner with the ultimate goal of speeding up your computer. And what's the use of cleaning something that hurts performance? Even when it is some nanoseconds.

 

[MrG]

Let's try and clear this up...

 

The prefetch feature within XP essentially creates a .pf file every time an EXE is run. This records the way the program loads and saves this data to optimize it in the future. (It's a bit more complicated but that's essentially it.)

Now these files will stay around on the system until the 128 pf file threshold has been reached. XP will then start deleting the old ones for you. The problem is that most users only have around 40-70 programs and services that they run on a regular basis. Which means the prefetch data will remain for an additional 58 to 88 programs before they get deleted. This will mainly include system updates and demo software, that are only run once or have been removed. You'll also have a record of all the exe filenames you've run (including any bits of dubious software!)

 

CCleaner will remove the prefetch pf files that haven't been accessed in the last 2 weeks, so removing the old and unused ones, but leaving all the programs you use most as fully optimized. Granted this will only save you a small amount of diskspace, and isn't protecting your privacy to the extent of IE History cleaning, but then the prefetch cleaning is only a minor part of CCleaner.

 

I know fully well you could say, "what about the fact it will delete the prefetch data for the program I only run once a month?"... or "what if I go on holiday for two weeks and then come back?"... or "I've turned off the LastAccessedDate property on my file system so it deletes all the pf files." ... or "I'm in love with my .pf files and don't want anyone to touch them!"

If you think these factors affect you or are highly important then I'd thoroughly recommend you turn prefetch cleaning off, if not then leave it the box checked.

 

Either way in the vast majority of cases running the prefetch cleaning option in CCleaner will optimize the system (reduce the number of unnecessary files) and not degrade performance.

[Greenknight]

Locking that thread was, if anything, overdue. It had long since degenerated into pointless argument and name-calling.

[Mastertech]

The problem is that most users only have around 40-70 programs and services that they run on a regular basis. Which means the prefetch data will remain for an additional 58 to 88 programs before they get deleted. This will mainly include system updates and demo software, that are only run once or have been removed. You'll also have a record of all the exe filenames you've run (including any bits of dubious software!)

The prefetcher automatically cleans uninstalled applications and remaining files take up next to no space..

 

CCleaner will remove the prefetch pf files that haven't been accessed in the last 2 weeks, so removing the old and unused ones, but leaving all the programs you use most as fully optimized. Granted this will only save you a small amount of diskspace, and isn't protecting your privacy to the extent of IE History cleaning, but then the prefetch cleaning is only a minor part of CCleaner.

It shouldn't do this at all. It shouldn't remove any application that is still installed on your machine. It removed applications I use everyday. It is removing files based on the file date. It should only be removing applications that are no longer installed on your system which the prefetcher does automatically. The space saving argument is useless since you want a PF file for ANY application you have installed incase you run it again.

 

I know fully well you could say, "what about the fact it will delete the prefetch data for the program I only run once a month?"... or "what if I go on holiday for two weeks and then come back?"... or "I've turned off the LastAccessedDate property on my file system so it deletes all the pf files." ... or "I'm in love with my .pf files and don't want anyone to touch them!"

If you think these factors affect you or are highly important then I'd thoroughly recommend you turn prefetch cleaning off, if not then leave it the box checked.

It shouldn't even exist at all there is no reason to delete these files.

 

Either way in the vast majority of cases running the prefetch cleaning option in CCleaner will optimize the system (reduce the number of unnecessary files) and not degrade performance.

No it UNoptimizes the system by deleting .PF files for applications you use everyday. Anyone can test this themselves. And this should have been tested to begin with.

[Tarun]

"MasterTech", I advise you drop it. He has answered everything very clearly. If you have so many gripes about the software, stop using it and stop coming to the forums. It's that simple.

[Mastertech]

I advise you read how prefetching works. Anyone can test what I said, what are you afraid of? This is a serious issue and I will not drop it until it is corrected. Thus the warning on my site.

 

CCleaner DOES NOT remove applications that were not used in two weeks it removes PF files with over a two week date from when they were created which is ridiculous and hurts application performance.

 

Why would you want to slow you system down?

[Tarun]

It doesn't slow you down. My machine is running faster than when I got it.

 

And guess what?

 

Prefetch is disabled and the folder is empty.

[Mastertech]

Of course you system will run without it except it will run faster with it enabled. It can shave 5-20 seconds off an applications load time. Deleting the PF file for the applications cripples this optimization until the file is created again.

[Tarun]

Reread my above post.

 

My prefetch is off and it's running FASTER than before when I had prefetch.

 

Does this make sense or do I need to spell it out for you?

[Mastertech]

That is BS. I've timed this on numerous systems and the results are the same a 5-20 second improvement in application load times. Anyone who has had prefetching enabled properly can test this themselves.

[Mastertech]

Oh and it is NOT nanoseconds. Anyone with Prefetching properly enabled can test this. Prefetching has to have been running and the application started at least three times, the defragmenter also has had to have been run to layout the associated files. I timed Avant Browser and it took 6-7 seconds to load. I then deleted the Avant Browser Prefetch file and cleared my RAM (important) then relaunched Avant Browser it took almost 12 seconds to load. So it is clearly NOT nanoseconds but seconds which is a significant difference.

 

After it is run the Prefetcher creates the file back again. So subsequent launches are optimized again. But why woud you willfully kill application load times every two weeks? It makes no sense. It is like forced unoptimizing.

[rridgely]

Mr.G has given you his explanation about why he chose to put this option in CCleaner. It is up to him not us what abilities CCleaner has. He has given his point as to why he will keep prefetch cleaning in CCleaner. So to continue carrying on this discussion is pointless.

[Mastertech]

No it is not, what he said is not happening nor should it even if it was doing what he said it should be:

 

CCleaner will remove the prefetch pf files that haven't been accessed in the last 2 weeks, so removing the old and unused ones, but leaving all the programs you use most as fully optimized. Granted this will only save you a small amount of diskspace, and isn't protecting your privacy to the extent of IE History cleaning, but then the prefetch cleaning is only a minor part of CCleaner.

CCleaner is removing any prefetch file that was created over two weeks ago which eventually will be any application you have installed.

 

I've stated clearly with testable results as to why no PF file should be removed for any installed application.

 

If you don't understand any of this then tell me where and I will explain further.

[MrG]

[Thread closed]