heinz wrote:

I agree, if you have enough RAM you can todo so, but in "My case" the machine is a "working-horse" and not a dedicated cruncher, so I have a reserve, if some app want more ram, and remember, I divided the ram half for crunching and half for the apps and on this machine I run more app's parallel, crunching, cut films, looking TV, compile some stuff, etc., and all this is running parallel.

I was actually referring to a work-horse and not a dedicated cruncher.

jason gee wrote:

Note that historically, the performance under win95, IMO from where these rules of thumb originate, was unstable enough to warrant minimising disk access, and OS issues addressed by programs such as photoshop suggested using a 'fixed size' to minimise kernel page file restructuring time during critical operations.

Actually the rule of thumb came around about Windows 3.0~ish. As a matter of fact, on a fresh install of Windows 3.0, if the Setup program detected enough hard drive space, it would "recommend" a permanent swap file and it would be set to 2.5x the amount of physical RAM.

Windows 95 attempted to 'make things better' by always using a temporary swap file that could expand and shrink as needed (just like in Windows 3.x). The decision to go this route was fueled by many support calls from Windows 3.1 users calling and asking what the large WINSWP.386 file located in the root drive was for, and why every time they deleted it, it was recreated. This also fueled complaints that Windows 3.x was a disk space hog.


Still, I fully acknowledge that it's probably a non-issue these days, but my old tendencies stay with me in that I still don't believe in setting a swap file for anything larger than necessary. Not necessarily to save disk space but to simply to keep things tidy and manageable. In Windows 3.1 - 98SE I have been known to keep my swap file around half my physical RAM to the same size of my physical RAM depending on how much I had installed at the time and what my needs were.

ML1 wrote:

Do you have a definite recommendation?

Not a definitive one, no. As I said, the best way to find out exactly how much you need is to open even single app that you plan on using simultaneously and measuring how much swap space is actually used, then reducing the swap file (or enlarging it as the case may be) to slightly larger than what is being used.

So if you have 8GB of RAM and you open up every single application you ever plan on using at once, and you notice that you still haven't even touched your virtual memory, setting it to 1/2 to 1/4 your available RAM would be perfectly reasonable, IMO. Whereas if you have 1GB of RAM and you find yourself needing an additional 1.5GB of virtual memory to run your programs, setting your swap file to perhaps 2GB would be reasonable in that situation as well.

ML1 wrote:

And does it matter?

No, not for the 'average' person, as pointed out. But for computer techies, I feel it is something important to consider as part of 'optimizing' a machine.

thanks all,
I will lookup and try todo so.
commit charge peak shows till now something more than 2,2GB used 12,81% of total 16
I think it will go up a bit with the time and depends what I'm doing.
maybe a value of 4 to 6 is enough.
I did not set the value 16 by hand, Vista choosed this alone during installation. So I assumed it has a good value.
thanks for your thoughts.. yes it is important to run with optimized values.
Paging shows:
Page Fault Delta = 371
Page Read Delta = 0
Page File Write Delta = 0
Mapped File Write Delta = 0
CPU and I/O:
Contest Switch Delta = 1903
i/O Read Delta = 12
i/O Write Delta = 12
I/O other Delta = 284
---------------------
This is shown, if the machine runs alone crunching, no other app is running

regards heinz
edit;typo

Roomtemp = 23 Celsius, humidity = 92%, FB-DIMM sensor = 60 Celsius.
CPU max 67, min 54 nice temps, measured with Coretemp
Avg credit = 4,935.10
Total Credit = 96,906
so far this is ok.
-------------------
I would not built the supercruncher, but a good "working horse" which this machine really is. The crunching is always a free additional.
With Vista64 Ultimate I'm happy so far, I can all do what is important for me.
Streaming Video, looking and recording TV, cutting films. Scan, collect and work with my pictures with different programs(Photoshop included) and do DTP and prepress. Last not least I must install some virtual printing machines like IP4000, IBM InfoColor 100, IP60, and QuarkXpress to handle Postscript and AFP-prints.
Then I don't need my other file-servers and old Mac's anymore again.
It is important for me todo all my work, (programming, compiling, optimizing, DTP and Printing-service, File sharing-service, Internet, my scientific work, and my personally reasearch interests on this machine together with my old P4 2,66GHz Northwood.
-------------------------
some technical:
Since I have built in the OCZ-RAM cooler, I dont need the two big fans of the CASE. Had never thought this before. Now you hear still a light noise from the 3 Disks, but when the machine come down from my desk to the bottom it is nearly nothing to hear. Therefore I used a passive cooled Graficcard too.. the Sapphire HD3870 Ultimate with it's 320 streaming processors runs great.
Next step is streaming the Videos to my HDI-TV...
So everybody of us has his own individual demands.
This machine meets all requirements I have.

heinz

The earliest mention of the 1.5 to 2 times system ram virtual memory size that I recall, stems from readme files in early windows versions of Adobe photoshop,

It was actualy an Adobe recomandation over several years (~1996 to ~2001) for their complete range of graphics products.
I should still have that whitepaper somewhere.

Do you have a definite recommendation?

Below 1Gb internal memory the adobe recomendation is in my opinion still valid.
It was a little bit more complicated than just system ram X2.

First there was a little table:

1 Applications | 1.5
2 Applications | 2.0
3 Applications | 2.5
4 Applications | 3.0

To determine paging file size lookup the number off aplications and multiply system ram by the specified factor.
Set this as starting size and miltiply again to get the maximum size.

Example (running 2 aplications):

256 x 2 = 512 <--- Start size
512 x 2 = 1024 <--- Maximum size

By experience i know a factor of 3.0 was sufficient for almost any system.
Comming with the introduction of several Gb of internal memory new insights have come.
For instance a windows 2000 or XP system will often not allow paging files larger than 4Gb.

---

Hi,
I tell you now how my poor P4 Northwood 2,66MHz
equipt with 2 ATA-disks(120GB + 250GB) + sometimes 1USB disk 120GB
1GB real MEM (2modules a 500MB)(max 2GB are possible with still two slots, a really poor board)
AGP Nvidia GeForce4 Ti 4200,
1 CD-burner + 1 DVD-burner, + 1 tape-Recorder, + 1 TV-card
my installed printers
my swapfile
Running XP-home,
almost my "working-horse" runs following software packages:
it is installed todo:

1.-My DTP prepaire Job..
QuarkXpress Passport, FlightCheck Professional 5.8, Adobe Distiller, Adobe Reader, Acrobat Exchange, Adobe Photoshop, PhotoStudio, and some other picture software from Ulead + GhostScript + some different printers for output

2.-My CD+DVD+Film hobby
AudioGrabber, AudaCity, CloneCD, Nero6, SmartRipper, VideoStudio9, PowerCinema to recording over SAT-TV(mpeg2)

3. My programming optimizing and development environment
Microsoft SQL-Server 2005
Microsoft Platform SDK for windows Server 2003 R2
Microsoft DirectX SDK 2008
Visual C++ 2005 ExpressEdition
Visual C++ 2008 ExpressEdition
Visual C++ 2009 ExpressEdition
Developer Express: DX-Core, Refactor C++
Tortoise CVS
Tortoise SVN
NvidiaSoftware: Cg Toolkit, SDK 9.5, CUDA SDK, NPerfHUD4, NPerfSDK, CUDA ToolKit
INTEL, Compiler10, IPP, MKL, TBB, VT
GAME Creators: Dark GDK
MS Assembler
Html Editor

4. The normal Microsoft package: a full Office package, Works

5. Security: different security programs + BackupSoftware: NortonGhost

6. some fun programs

7. seti with its program package.
-------------------------------------
Till I built the V8-Xeon, I used all my programs and parallel runs seti on this small machine. Never I stopped the boinc service when I worked.
But the swapfile is 4096MB, I dont know if this as the optimal value, but with it the machine works several years to my satisfaction.
till now this machine has:
Avg Credit: 392.14
Total Credit: 201,540
active since: Feb 25 05

regards heinz ;-)

---

D5400XS V8-Xeon

... For instance a windows 2000 or XP system will often not allow paging files larger than 4Gb.

Now that's a good question...

For 32-bit (Windows) systems, you have a 4 GByte limit on addressable memory space. Hence, there is no point for installing more than 4 GByte RAM for a 32-bit Windows (and you don't even see that much when IO mapping and tables are subtracted).

So... How does 32-bit Windows handle more than 4 GBytes for physical RAM + Virtual RAM?

Happy crunchin',
Martin

---

See new freedom: Mageia Linux
Take a look for yourself: Linux Format
The Future is what We all make IT (GPLv3)

Hi,
made a try on my poor P4 266GHz
when I write this, following programs are active
and this shows the swap-using
not so much as I thought, so we can reduce the swap-file.

thanks all who commented it.

heinz

---

D5400XS V8-Xeon

Just under 5000 RAC on that machine, IMO not bad for 2GHz at all Heinz ;D

---

"Living by the wisdom of computer science doesn't sound so bad after all. And unlike most advice, it's backed up by proofs." -- Algorithms to live by: The computer science of human decisions.

Hi Jason,
when the V8-Xeon is crunching and no additional software is running, it shows swap-using
hmmm. .. it uses around 2GB
any comments are welcome

heinz

That's probably Windows paging out currently unused OS and DLL type stuff, effectively a way of freeing up system RAM for foreground applications, possibly also caching things in the page file that may be needed but not immediately. If you intend to run database and server type services, there *may be* a few configuration options to look at to make it more server-like operation of keeping stuff in RAM. At least that's how it is with XP Pro, I have no idea whether similar configuration settings apply for Vista.

Jason

---

"Living by the wisdom of computer science doesn't sound so bad after all. And unlike most advice, it's backed up by proofs." -- Algorithms to live by: The computer science of human decisions.

today 19 hour temperature = 26 Celsius, humidity = 80%
The heaven is already black again, looks like the next thunderstorm is comming.

Yesterday I made some complete partition-backups of the system in preparation to build the RAID. If I look into the BIOS and I choose RAID then I can not exclude any disk. Disks are on SATA port 0,1,2. till now still disk on pot 0 is used to install Vista64 in a 50GB partition. The other two disks are not partitioned till now.
Thought to use one disk with a boot-loader(Acronis) for different OS'ses resides each in its own partition, all on the disk connected to port 0.
Other two disk to use for a stripe set.
With 3 disks(minimum) I could set up a RAID5 too... but I'm still undecided todo so.
Did anybody of you already create a RAID over the BIOS settings ?
Your suggestions are welcome

thanks heinz

22:25 hour
temperature = 21 Celsius, humidity = 100%, light rain
FB-DIMM sensor = 60 Celsius
CPU max 68, min 56 Celsius
the Bootmenue and Acronis OS Selector is installed now.
Next step is make the raid5

heinz

today 19 hour temperature = 26 Celsius, humidity = 80%
The heaven is already black again, looks like the next thunderstorm is comming.

Yesterday I made some complete partition-backups of the system in preparation to build the RAID. If I look into the BIOS and I choose RAID then I can not exclude any disk. Disks are on SATA port 0,1,2. till now still disk on pot 0 is used to install Vista64 in a 50GB partition. The other two disks are not partitioned till now.
Thought to use one disk with a boot-loader(Acronis) for different OS'ses resides each in its own partition, all on the disk connected to port 0.
Other two disk to use for a stripe set.
With 3 disks(minimum) I could set up a RAID5 too... but I'm still undecided todo so.
Did anybody of you already create a RAID over the BIOS settings ?
Your suggestions are welcome

thanks heinz

I found now where I must look up to configure the RAID
heinz

... For instance a windows 2000 or XP system will often not allow paging files larger than 4Gb.

Now that's a good question...

For 32-bit (Windows) systems, you have a 4 GByte limit on addressable memory space. Hence, there is no point for installing more than 4 GByte RAM for a 32-bit Windows (and you don't even see that much when IO mapping and tables are subtracted).

So... How does 32-bit Windows handle more than 4 GBytes for physical RAM + Virtual RAM?

Happy crunchin',
Martin

Virtual memory is mapped out of physical RAM, thus it can be addressed independently in 'chunks'. The concept is similar to EMS memory back in the days of DOS using a 64KB window to map portions of EMS into physical RAM (often in the UMA if you could get your EMS window loaded high).

Some applications use virtual memory to use more RAM while not requiring so much from the system by paging out portions of code to the swap file and loading them back when needed. This is why disabling the swap file can actually cause some programs to crash. Those apps that depend on the swap file for extra address space will find none and exit (sometimes not so gracefully).

The actual MMU in all 286 and higher compatible processors have a separate addressing mechanism for physical and virtual memory (respectively). Obviously, the i386 through the Pentium have 32bit physical addressing space, but they also have a 46bit virtual address space. The Pentium Pro to current x86 processors increased the physical address space to 36bit but kept virtual the same.

64bit processors increase the physical address space to 40bits (can be increased in later processor revisions if necessary) which allows access to 1 TiB of RAM or 2^40 (with a maximum increased capacity of 4 PiB or 2^52 for 52bit addressing). Virtual memory was increased to 48bits (2^48 or 256 TiB of virtual memory accessable) with future revisions that can be allowed to access 64bit (2^64 or 16 EiB) of addressable virtual memory.

Virtual memory then becomes an OS limitation as to how its handled and how much is allowed. Windows x86 can have 8 paging files provided each one resides on a different partition, each up to 4GiB in size for a total of 64GiB of virtual memory, all still addressable in the standard 32bit logical address space (albeit slower due to the paging in and out of RAM/hard disk).

64bit versions of Windows allow for larger paging files per drive natively. I believe the limit is the entire 48bit virtual address space, but this has not been confirmed yet.

When I read the doku to install the "Intel Matrix RAID", found following important point

3. The following operating systems are not supported:

Any version of the following Microsoft operating systems:
- MS-DOS
- Windows 3.1
- Windows NT 3.51
- Windows 95
- Windows 98
- Windows Millennium Edition (Me)
- Windows NT 4.0
- Windows 2000 Datacenter Server
- Windows 2000 Professional

Any version of the following operating systems:
- Linux
- UNIX
- BeOS
- MacOS
- OS/2
---------------------------------------------------------------------
huuh... I would install LINUX Fedora9 and NT4-Server parallel to the Vista64 and Server2008
Reading doku of Server2008 a RAID is prerequisited to install ...
What say the Linux gurus to this ?
Thought always Linux can handle raids very well...but perhaps no Matrix Raid
A solution could be add more disks, and reside Fedora9 and NT4-Server onto a disk not belongs to the RAID...uuuuufff

hmm or better make a RAID, install Server2008 and make some virtual machines with NT4 and Fedora9...

your suggestions are welcome

heinz

when I write this, following programs are active

In this case you should better be looking at the prozesse tab.
In your case you show only programs with direct user interfaces.
On the Ansicht menu you shuold have an option like spalte auswählen (choose collums) which alows you to display memory and pagefile usage for each process.
This is also posibble by using process Explorer

and this shows the swap-using

You should be running and using the applications for several hours.
Watch and take note of the Peak value under Commit Charge (K).
Commit Charge reflects Phisical and Virtual Memory combined.
This value will tell you how much memory is actualy used.
Limit may vary if the paging file is set with different start and maximum sizes.
Considder tuning your paging file to somthing above peak value (like peak ~90%).

---

... For instance a windows 2000 or XP system will often not allow paging files larger than 4Gb.

Now that's a good question...

Virtual memory is mapped ...

Virtual memory then becomes an OS limitation as to how its handled and how much is allowed. Windows x86 can have 8 paging files provided each one resides on a different partition, each up to 4GiB in size for a total of 64GiB of virtual memory, all still addressable in the standard 32bit logical address space (albeit slower due to the paging in and out of RAM/hard disk).

64bit versions of Windows allow for larger paging files per drive natively. I believe the limit is the entire 48bit virtual address space, but this has not been confirmed yet.

Thanks for a very good answer.

So, just to get this right:

On 32-bit Windows, you can have a maximum of 4 GByte physical RAM (not all of which gets used), and additionally up to 8 page files of 4 GBytes each (which can be fully utilised), and then up to say 7 applications can address a full 4 GBytes each by utilising virtual memory?

Or can an application address it's 3 GByte or so physical RAM and additionally a further 4 GBytes of virtual RAM?


(But then again, why are we still languishing in the world of 32-bits?! Ok, so there's old software that is 32-bits and doesn't run on anything other than The One OS it was hacked for...)


Regards,
Martin

---

See new freedom: Mageia Linux
Take a look for yourself: Linux Format
The Future is what We all make IT (GPLv3)

When I read the doku to install the "Intel Matrix RAID", found following important point

3. The following operating systems are not supported:

Any version of the following Microsoft operating systems:
[...]

Any version of the following operating systems:
- Linux
- UNIX
- BeOS
- MacOS
- OS/2
---------------------------------------------------------------------
huuh...
[...]
Thought always Linux can handle raids very well...but perhaps no Matrix Raid...

Linux implements "Linux software RAID" (Linux native RAID) very well and very effectively.

There's lots of RAID hardware that is 'proprietary' and you are completely dependant on what the manufacturer does. Note also that there are many "false RAID" combos that are a slightly enhanced controller but dependant on BIOS/drivers to do the RAID cleverness.

I gave up with hardware and pseudo-hardware RAID long long ago. You can never be sure how your data is spread around the disks. You never know how well recovery from failure will work. You can even have the controller itself scramble your data and not tell you!

In contrast, the native Linux RAID is well proven, works well, and you know how your data is spread so that you can recover your data directly from each disk if you need to. (No proprietary 'secretive confusions', and no loosing the arrays if you change failed hardware.)


Some manufacturers do support Linux (or BIOS) drivers for their RAID hardware. I'd rather not waste the money of suffer the cost of yet another 'unknown'. You can use the cost saving to buy more disks or to buy a faster system so that the Linux RAID works faster in the first place!

Just my opinion. (I prefer not to trust to 'magic'.)

Good luck,
Martin

---

See new freedom: Mageia Linux
Take a look for yourself: Linux Format
The Future is what We all make IT (GPLv3)

On 32-bit Windows, you can have a maximum of 4 GByte physical RAM (not all of which gets used), and additionally up to 8 page files of 4 GBytes each (which can be fully utilised), and then up to say 7 applications can address a full 4 GBytes each by utilising virtual memory?

The default behavior in most apps is to let the OS manage all swapping as necessary. But if a program were specifically coded to use swap space for certain code/data, and were programed to use up to 4GB of swap, then yes, it is possible. Of course, most coders would never (or be insane to) use that much virtual memory due to the overall performance of their app being dragged down by slow hard drive performance. An application has no way of knowing how much virtual memory is actually allotted, so requesting 4GB of virtual memory from the OS would require the OS to grow a swap file if one wasn't large enough to the size requested by the app. One way to help performance would be to request the virtual memory needed then slowly add code/data as needed into the space.

Or can an application address it's 3 GByte or so physical RAM and additionally a further 4 GBytes of virtual RAM?

The actual limit per the 32bit spec is 2GB of physical RAM. 3GB can be used by modifying the address space (3GB user / 1GB system), but this breaks the original spec and can cause problems for some apps.

But yes, it is possible to have an app utilize the entire 2GB physical address space and an additional 64GB of virtual (the app will not know each swap file is located on a different partition, instead it will see it all as one contiguous 64GB of virtual memory).

And if a developer does that on my system, I will hunt him down and kick him.

Don't ask me how to actually set this up in the program though as my coding skills are about as good as my German.

(But then again, why are we still languishing in the world of 32-bits?! Ok, so there's old software that is 32-bits and doesn't run on anything other than The One OS it was hacked for...)

Really? I'm only aware of apps that have lingering 16bit code (either a DLL, DRV or executable) that won't work on 64bit.

15:10 hour, roomtemp=22, humidity=100%, rather cloudy, fine rain..
FB-DIMM sensor shows 60 Celsius
CPU's max 67 min 54 Celsius
-------------------------------------------------------
Try to install NT4-Server int a prepaired 2GB partition. Started with the NT4Server CD in the SATA-DVD unit. It starts, but then shows: --->

HAL: No IO APIC Found
HAL: This HAL.DLL requires an MPS version 1.1 system
Replace HAL.DLL with the correct HAL for this system

uuuhh, every day new surprises...I don't believe that any version of NT4 support this new chipset of the board...so I must think about a other solution to install NT4. Any suggestions... perhaps under Server2008 as virtual machine.
---------------------------------------------------------
My installed Bootmenue "Acronis OS Selector" works fine.
It resides in a extra 2GB partition, to be undependent from any OS installation.
It's a nice matter, together with Acronis Disk Director, you can easyly copy and restore the whole partition as compressed ISO and a lot other special functions too.
See http://www.acronis.de http://fr.acronis.com/ for full functionality.

heinz