Read ahead and behind optimisation - I want to increase it

[esecallum]

i have turned the read ahead optimization in windows me to maximum which means it is 64 k now....but i want to make it read/cache even more into ram like a 1, 2,...even 20 megabytes to be stored in ramfor later use.

how can i do this.

microsoft went with the 64k figure as RAM was very scarce at the time....now it is not...i have 512 k ram and i want it to improve disc performance.

is there a registry hack/modification which can increase read ahead to some other bigger value then 64 k?

has anyone tried this?

Edited January 27, 2009 by esecallum

[esecallum]

Well?

As you may know disk performance is impaired by a low setting for read ahead due to above reasons, causing more read operations. By storing the larger amount of info in ram, repeat returning to the hard disc for additional bits of the same file would would be reduced.

i am amazed no one has thought of this.

there must be a registry hack to increase the read ahead optimization from 64 k to a larger value.

i did a Find search in the registry using REGEDIT using readahead as the search word.

this is what i found:-

"readahead thereshold 00 00 01 00"

anyone knows what this means or we can change it?

[charly]

Well?

this is what i found:-

"readahead thereshold 00 00 01 00"

anyone knows what this means or we can change it?

The registry setting is ----

[HKEY_LOCAL_MACHINE\System\CurrentControlSet\Control\FileSystem]

"ReadAheadThreshold"=hex:00,00,16,00

-----------

This is the best setting for my machine, maybe to high for you. 16 = 1024

just change "00 00 01 00" to "00 00 16 00"

other settings are ---

64 = 4096

32 = 2048

16 = 1024 ------ this is my best setting

8 = 512

4 = 264

2 = 128

1 = 64

Hope this helps you,

Charlie

[rainyd]

You can tweak system settings using freeware Cacheman 5.50, available from here: http://www.outertech.com/index.php?_charis...roduct&id=2

Edited January 29, 2009 by rainyd

[thydreamwalker]

Auto-Patcher98 :Has a System Tweaks Module so you can Tweak Safely and it uninstalls if problems arise in future hmmmmmmmm

[charly]

Auto-Patcher98 :Has a System Tweaks Module so you can Tweak Safely and it uninstalls if problems arise in future hmmmmmmmm

Yea, but they only let you go to 512!

[starcraftmaster]

where do we get Auto-Patcher98

and will it work with windows me and can you just install the System Tweaks Module

[ldb]

"This is the best setting for my machine, maybe to high for you. 16 = 1024

just change "00 00 01 00" to "00 00 16 00"

How do you tell/test for what is the best setting?

Thanks

[jaclaz]

As a "general" rule, when you are looking for something 9x and Me related, check first on MDgx's pages :

http://www.mdgx.com/newtip18.htm

tip #2

jaclaz

[Drugwash]

For some reason, the value for the above-mentioned key was 00 00 00 ff on my 98SE system.

I changed it to 00 00 08 00 since I only have 256 MB RAM and will see the result.

[ldb]

Well?

this is what i found:-

"readahead thereshold 00 00 01 00"

anyone knows what this means or we can change it?

The registry setting is ----

[HKEY_LOCAL_MACHINE\System\CurrentControlSet\Control\FileSystem]

"ReadAheadThreshold"=hex:00,00,16,00

-----------

This is the best setting for my machine, maybe to high for you. 16 = 1024

just change "00 00 01 00" to "00 00 16 00"

other settings are ---

64 = 4096

32 = 2048

16 = 1024 ------ this is my best setting

8 = 512

4 = 264

2 = 128

1 = 64

Hope this helps you,

Charlie

Cacheman also only lets you go up to 512. Still waiting on information on how how to test what is the best setting.

[ldb]

I edit my response about cacheman, the slider only went up to 512 on my initial view. When I manually edited the registry and increased it to 1024, a new slider appeared in cacheman with my setting listed and able to be lowered to 512 and increased much higher.

[esecallum]

I edit my response about cacheman, the slider only went up to 512 on my initial view. When I manually edited the registry and increased it to 1024, a new slider appeared in cacheman with my setting listed and able to be lowered to 512 and increased much higher.

could you report how large file copy/paste operations on the same hard drive are affected?

are they faster/slower/improved.

i will do some experiments shortly by copy/pasting 1 gb files to different and same partition after adjusting the from 4k to 64 to 512 k to 1024 k and so on...

i will report later.

is your hard disc i/o operations improved?

[ldb]

I edit my response about cacheman, the slider only went up to 512 on my initial view. When I manually edited the registry and increased it to 1024, a new slider appeared in cacheman with my setting listed and able to be lowered to 512 and increased much higher.

could you report how large file copy/paste operations on the same hard drive are affected?

are they faster/slower/improved.

i will do some experiments shortly by copy/pasting 1 gb files to different and same partition after adjusting the from 4k to 64 to 512 k to 1024 k and so on...

i will report later.

is your hard disc i/o operations improved?

I have asked a couple of times how to test for determining the correct size. I would imagine that your system configuration would have a lot of influence on it, but am not sure what tests would tell you when you went too big for example. I am up to 1024 now with no discernible ill effects yet. I have 512 or ram so there is plenty of room for buffers. My system is fairly speedy anyway so I am not too sure how to measure any improvements that may have occurred. The programs I run before shutdown yesterday seemed a little more snappier.

[RetroOS]

Another factor with performance is the Write Behind (writeback) Cache.

By default, this is enabled on internal, non-removable drives only (basically PATA/SATA/SCSI drives).

To enable writeback caching on all drives:

[HKEY_LOCAL_MACHINE\System\CurrentControlSet\Control\FileSystem]

"DriveWriteBehind"=hex:ff,ff,ff,03

However...

WARNING: Do not remove 'removable' or external media until at least five (5) seconds after the last drive activity.

Doing so could cause corruption from pending unwritten data - the same effect you would get if you pulled a flash drive out while writing a file to it - with the difference that the copy/write will appear to have finished from Windows' point of view.

As long as you following this warning, then you can expect external media to improve in performance - especially during writes of many smaller files.