Windows 7 Forums

Welcome to Windows 7 Forums. Our forum is dedicated to helping you find support and solutions for any problems regarding your Windows 7 PC be it Dell, HP, Acer, Asus or a custom build. We also provide an extensive Windows 7 tutorial section that covers a wide range of tips and tricks.


Windows 7: Is it possible to create a C: drive with 64K clusters?

11 Aug 2009   #11
kolotyluk

Windows 7 Ultimate 64-bit
 
 

Quote   Quote: Originally Posted by Antman View Post
Also note: You may actually reduce the performance of your RAID0 with 64k blocks. Any files smaller than 64k will reside on a single disk within the volume, disaffecting the benefit of multi-head seeks/reads/writes.
Yes, this is not ideal for small files, but the application I have is based on processing images hundreds of megabytes (or larger) so I'm trying to optimize large file performance.

What I am trying to understand is if cluster size impacts large file performance. In this particular case I'm curious if matching the cluster size to the RAID block size helps at all - in such a case each file system operation to the disk will equal one RAID operation (I imagine).

Cheers, Eric


My System SpecsSystem Spec
.
11 Aug 2009   #12
Antman

 

Quote   Quote: Originally Posted by kolotyluk View Post
I'm curious why you think this would have an effect? The block size of the RAID is already 64K, so the I/O operations over the PCI bus would already be 64K wouldn't they?

The system boots fine when C: is 4K clusters (the default), but not for 64K clusters - which is why I suspect a boot loader problem.

Thanks for the warning, but there is nothing I need to archive as this is a test box I'm playing with and I've been reinstalling Windows 7 from scratch each time.

Cheers, Eric
You are waiting for two or more distinct physical actions to occur and register within the disk controller. Increase the latency value to compensate for a longer (combined) wait state.

A long standing adjustment known to address similar issues.

BUT NOT ON MS! Never mind. Unconfirmed but from an engineer I trust - private communication not for publication.

I was just directed to a reference that MS, beginning with XP SP2, only allows a max of 8k clusters on the boot volume. XP SP1 was the last MS OS that will allow this.

M3a79-t raid problems - Guru3D.com Forums
See post #4
My System SpecsSystem Spec
11 Aug 2009   #13
kolotyluk

Windows 7 Ultimate 64-bit
 
 

Quote   Quote: Originally Posted by dinesh View Post
oh i was talking about the strip size. thanks for the correction.
The default cluster size for NTFS is 4K - that is all file system operations to the disk controller are performed 4K bytes at a time. With 64K clusters, operations are performed 64K bytes at a time.

The default block size for many RAID systems is 128K (mine included). This means RAID controller operations to disk are performed 128K bytes at a time - or 128K is written to each disk in the RAID until moving on to the next disk.

I don't like using the term stripe size as different people use it differently. To some people stripe-size = block-size * number-of-disks, whereas other people assume stripe-size means block-size.

Looking at various benchmarks I have found that block sizes over 64K usually offer little extra performance increase. This is likely because many I/O controllers have been optimized to perform operations 64K bytes at a time - typically 8 DMA operations of 8 KB at once before having to reprogram the DMA controller for the next operation.

Cheers, Eric
My System SpecsSystem Spec
.

11 Aug 2009   #14
kolotyluk

Windows 7 Ultimate 64-bit
 
 

Quote   Quote: Originally Posted by Antman View Post
You are waiting for two or more distinct physical actions to occur and register within the disk controller. Increase the latency value to compensate for a longer (combined) wait state.

A long standing adjustment known to address similar issues.

BUT NOT ON MS! Never mind. Unconfirmed but from an engineer I trust - private communication not for publication.

I was just directed to a reference that MS, beginning with XP SP2, only allows a max of 8k clusters on the boot volume. XP SP1 was the last MS OS that will allow this.

M3a79-t raid problems - Guru3D.com Forums
See post #4
OK, I just tried formatting C: with 8K clusters, and I get the same "A disk read error occurred" when the system reboots.

What did you mean by "XP SP1 was the last MS OS that will allow this?" Do you mean that prior to XP SP2 it was possible to have a boot volume with larger than 8K clusters?

Do you think I should still try tweaking the PCI latency?

Cheers, Eric
My System SpecsSystem Spec
11 Aug 2009   #15
RichB

Win7 x64 RTM
 
 
I did this in a trial

It took me some trial and error, but I managed to get the C drive to 64k clusters. You'll need to preformat the drive, and leave enough space for Win7 to create a boot partition of 100mb.
My System SpecsSystem Spec
11 Aug 2009   #16
Antman

 

Quote   Quote: Originally Posted by kolotyluk View Post
Do you mean that prior to XP SP2 it was possible to have a boot volume with larger than 8K clusters?

Do you think I should still try tweaking the PCI latency?
1. That is what my friend told me by phone this morning (I just happened to be speaking with him - I did not call to ask). I do not know otherwise. Throw in an XP <SP2 and try.

2. The setting is there for a reason. It is also a known adjustment to deal with some RAID/controller issues. Do I know if it will affect your situation - no. You have stated that no data is at risk. Estimated time on task: < 5 minutes. Time invested to this point: > 5 minutes.
My System SpecsSystem Spec
11 Aug 2009   #17
kolotyluk

Windows 7 Ultimate 64-bit
 
 

Quote   Quote: Originally Posted by RichB View Post
It took me some trial and error, but I managed to get the C drive to 64k clusters. You'll need to preformat the drive, and leave enough space for Win7 to create a boot partition of 100mb.
Sounds like what I'm looking for, but can you please give me some more details. Will windows automatically create the boot partition? Should I just leave 100 MB or so before the C: partition?

Cheers, Eric
My System SpecsSystem Spec
11 Aug 2009   #18
Antman

 

Quote   Quote: Originally Posted by RichB View Post
It took me some trial and error, but I managed to get the C drive to 64k clusters. You'll need to preformat the drive, and leave enough space for Win7 to create a boot partition of 100mb.
Did you use a method as described at Guru3D? Can you elaborate?
My System SpecsSystem Spec
11 Aug 2009   #19
kolotyluk

Windows 7 Ultimate 64-bit
 
 

Quote   Quote: Originally Posted by Antman View Post
1. That is what my friend told me by phone this morning (I just happened to be speaking with him - I did not call to ask). I do not know otherwise. Throw in an XP <SP2 and try.

2. The setting is there for a reason. It is also a known adjustment to deal with some RAID/controller issues. Do I know if it will affect your situation - no. You have stated that no data is at risk. Estimated time on task: < 5 minutes. Time invested to this point: > 5 minutes.
OK, I'll have to hunt around for an old XP installer - now I'm curious.

I checked the BIOS setting on my Dell Optiplex 960 - there is nothing there for the PCI latency.

Cheers, Eric
My System SpecsSystem Spec
11 Aug 2009   #20
Antman

 

Quote   Quote: Originally Posted by kolotyluk View Post
OK, I'll have to hunt around for an old XP installer - now I'm curious.

I checked the BIOS setting on my Dell Optiplex 960 - there is nothing there for the PCI latency.

Cheers, Eric
Dell=Don't Even LLook for mods.
My System SpecsSystem Spec
Reply

 Is it possible to create a C: drive with 64K clusters?




Thread Tools




Similar help and support threads
Thread Forum
Questions about Image backup and "Bad Clusters" & restore over network
1. I've been getting warnings that my hard drive is failing, and other diagnostics have reported there could be "bad clusters." I have an online backup of all my files, but I want to try an image restore. I following the Win 7 instructions for creating a backup. At the end of the process, the...
Backup and Restore
Create a permanant drive letter for USB Stick Drive
Can Someone please tell me how I create a permanent drive letter for a USB Stick Drive? Say Z: ?? So When I boot to it it will always go to that drive letter? Thank you Very much John
Hardware & Devices
Backup failure; Bad clusters
I was creating a system image backup last night and it failed because of bad clusters. Now i have 11 DVDs that were part of that backup. Do I have to start all over again?
Backup and Restore
How do you create a USB boot drive
I am sure this question has come up before and is very easily answered but I really need some help!!! Please could someone tell me how to make a bootable usb drive with windows 7. Please can you make the instructions really clear because I don't want to muck up!!! Any help much appreciated ...
Installation & Setup
recovery of bad clusters - any log?
I believe one of my external hd has developed some bad clusters and they do appear on a surface scan. So I ran Windows 7's "automatically fix file system errors" and "Scan for and attempt recovery of bad sectors". Is there a way to find out what bad clusters Windows found and recovered without...
Performance & Maintenance
clusters
since sector size is based on powers of 2, and clusters can be one or more sectors. is my hdd programed in a non-most basic of programming languages since it has like 43 million + sectors and is a mere 240GB in size?
Hardware & Devices


Our Sites

Site Links

About Us

Find Us

Windows 7 Forums is an independent web site and has not been authorized, sponsored, or otherwise approved by Microsoft Corporation. "Windows 7" and related materials are trademarks of Microsoft Corp.

Designer Media Ltd

All times are GMT -5. The time now is 19:11.
Twitter Facebook Google+ Seven Forums iOS App Seven Forums Android App