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System.ini IRQ Tweak

Windows 9x/ME
2001-03-31 (updated: 2009-12-08) by
Tags: , , , ,

The following tweak is not documented by Microsoft, and it is controversial whether it works at all. We have tested numerous times and it shows anywhere between 0 and 10% performance gain, which we consider inconclusive. We have received 100s of responses saying this tweak worked great, and 100s saying it's crazy, or it does nothing at all. We feel we should leave the information posted on the site in order to present our readers with all possible options for optimizing their throughput, however keep in mind we haven't been able to prove the validity of this particular tweak, and are not fully confident in the following information. Feel free to send us mail with your feedback. With all that said, it will not degrade performance of your system, and if you're willing to try and see how it works, here are the instructions:

 

In Windows 9x, you might be able to reserve a certain amount of RAM for specific IRQs (Interrupt Requests), which serves as a buffer to allow more stable operation of your device. Adding a 4Mb buffer to your Network Card's IRQ would ensure good overall performance and increase throughput with broadband Internet connections, such as DSL and Cable Modems.

Reserving RAM for your Network Adapter might prove very useful, especially during CPU intensive tasks, or while gaming online. For those with 500MHz or slower processors and 128Mb or less RAM, this tweak might show noticeable results at all times, including faster displaying of web pages and higher throughput. Even with fast processors you will get better overall performance, including smoother stream video, better transfers anywhere from 0 to 10%, with more noticeable results during faster transfers. Another good reason for using this tweak would be if you have a PCI NIC sharing IRQs with another device.

 

Step 1 - Find your Network Card's IRQ

In order to add the entry to your System.ini file, you'd first have to find your NIC's IRQ.

Right-click on My Computer icon on your Desktop, then left-click on Properties (a shortcut for that would be to press the 'Windows' + 'Pause' keys). Navigate to Device Manager and double-click on Computer. Under "View Resources" you will find a list of IRQs, each with description of the device that's using it. Note the IRQ number used by your Network Adapter.

Click to expand
Fig. 1.1 - Device Manager ('Window' + 'Pause' keys)
Click to expand
Fig. 1.2 - Finding the IRQ of your NIC


 

Step 2 - Adding the entry to System.ini

Once you've found the IRQ of your Network Card, you need to reserve some RAM for its use, by adding an entry to the System.ini file. You can edit the file in any text editor, however the easiest way is to use Windows' built in "System Configuration Editor".

Navigate to Start > Run and type sysedit . Find the [386enh] Section in the System.ini file and add Irq[n]=4096 under it, where [n] is the IRQ number of your NIC and 4096 is the amount of RAM you want to reserve in Kbytes. We recommend using 4096, however you can experiment with different values if you want. Save changes in the file, exit and reboot for changes to take effect.

Note: If you choose to try different values, keep in mind that reserving too much RAM for your NIC will decrease the amount of RAM available for applications, while reserving too little might not give the desired effect.

Click to expand
Fig. 2.1 - Editing System.ini

 

Additional Thoughts

The only negative effect of the System.ini IRQ tweak is that it will reduce the amount of RAM available for running applications a bit, by reserving some specifically for your Network Card's use. The gain in performance usually outweighs the negative effect by far, considering any Computer with 32Mb of RAM or more.

Keep in mind that if you add hardware to your system the IRQ of the Network Adapter might change, in which case you will need to modify the setting in System.ini.

In systems with multiple NICs, you might want to add the setting for both IRQs. Also, you could reserve RAM for other IRQs if you wish, just use common sense and don't forget it reduces the amount of RAM available for running applications.

If you are using an USB device, it does not have a specific IRQ, however you can try adding the entry using the IRQ of the USB Controller.

For internal Cable Modems, you'd have to add the entry using the IRQ of your modem, rather than the IRQ of a Network Card.

  User Reviews/Comments:
    rate:
   avg:
by anonymous - 2006-10-25 14:49
Hey

Just wanted to give feedback on the IRQ tweak you posted. I'm using a Realtek NIC and find that it works excellent. Along with a few other reg tweaks i've used this one is my fave. It does add some speed to slower systems (ie mine is a p3 850) and the pages come up right away, no choppiness or anything.

Great tweak.

--
Murphy had no law degree.
by tjs275x - 2006-11-09 11:26
This tweak is more bad then good. Once you edit the ini file and add the memory res to your network card. Users will see after some time using the internet (15 mins or so) he/she will find that the DNS will stop working. Once the DNS stops websites will not display but streaming or games will still work online. After you remove the tweak from ini things start working again.
by Philip - 2006-11-09 19:12
tjs275x, I believe this tweak is totally unrelated to DNS.
by anonymous - 2006-12-13 20:48
does this tweak require the MAXMEM= command?

no expert, no reason,i just thought of it and wondered if it would have any effect :D
by sudhagud - 2007-08-16 17:45
Very good

As tjs275x said above, i had a dns problem with 4096,
used 8192 and all worked fine, now I have set it to 32768 and LAN and internet speed is very good.

Irq[n]=32768
reboot and all is fine.

Cheers
by anonymous - 2008-01-23 04:58
Any use on WinXP?
by Nick - 2008-04-13 13:34
Thanks for the tip i have been suffering at the hands of my ISP after following the instructions and reboot later things have changed.
by anonymous - 2008-06-07 09:56
I tried it on win xp with my wireless card and it seems to work
by anonymous - 2008-12-24 03:48
ALWAYS GAVE A NICE SPEED INCREASE ON ALL MY COMPS. I HAVE 3 DIFFERENT TYPES OF COMPUTER SCIENCE DEGREES BY THE WAY ALSO. HELL I'M PISSED CAUSE I CANT USE THIS TWEAK IN VISTA;)
by anonymous - 2009-01-17 21:40
You can use this on Vista, just run cmd as admin and it will work
by thomas - 2009-02-15 10:46
i seem to not be able to open sysedit on windows me it comes up not found any suggestions?
by chris - 2009-05-26 09:16
works fine on my P4 3,2 Mhz 512 Mb RAM PC!I've got an 8 Mbit dsl connection and the improvement in browsing is obvious!
by cowater - 2009-06-30 20:01
how make this tweak on vista?
by Ahmad Saleem - 2009-07-07 02:21
This tweak also works in Window XP. you also done this through msconfig in Run.
by anonymous - 2011-02-20 09:26
What's the best value to put then? Thanks.
by anonymous - 2011-09-06 12:04
nice tweak
by Mundiall14 - 2012-04-23 00:33
When I typed sysedit on my win 7 pc nothing happened.
by Namit - 2012-08-03 13:04
Whenever im saving the file its saying Access Denied.
by Mundiall14 - 2012-08-14 02:14
I get the same "Access Denied" error message in Win 7
by anonymous - 2013-06-18 18:33
This tweak does nothing on OS's that are NT based ie NT4, 2000, XP, Vista, 7, 8 System.ini is only used in these OS's for compatibility with old applications.
by RONcCO - 2013-11-14 16:55
THIS TWEAK WORKS IN WINDOWS = ALL
IVE SPECIFICALLY WENT INTO ALL OF M$ WORKING SYSTEMS AND THIS WORKS WELL,,ALL YOU NEED TO B CAREFUL OF IS HOW MUCH ACTUAL RAM U HAVE TO SPARE----AND TO THOSE WHO CANT GET IT TO WORK - I MEAN- SYSTEM WONT LET YOU SAVE THEN OPEN UP INI AS ADMIN IN NOTEPAD THEN OVERWRITE!!
SHOULD HAVE NO PROBS IF FOLLOWED THIS AS STATED IN THIS SECTION!!

FYI == ALSO WORKS IN 8.1 HAHAHAHA MADE MY USB DONGLE GIVE ME , WELL I PAID FOR 15MBPS AND AFTER THIS TWEAK IM GETTING ACTUAL IN/OUT=10-13MBPS/10-11MBPS THATS 10-13 MBPS DOWN/10-11MBPS UP,,,B4 THIS I WAS ONLY GETTING ABOUT 900KBPS AND IM 350 FT THROUGH FIVE CONCRETE WALLS-- CAN I SAY THANKX GUYS NO I DONT NEED A BUFFER IT SEEMS !!--HD VIDS FROM ALL SOURCES PLAY INSTANTLY I DIDNT THINK IT WOULD WORK BCUZ IM ON A OLD XP RIG THAT I RE-RIGGED FOR W8 ONLY
by kerb - 2013-12-05 01:43
i wonder if this will work with -3 IRQ? how should i put in inside? IRQ-3=xx? will it work?
by Mike - 2016-04-30 22:49
Might I suggest editing the title to show that this is a w98 / ME setting?
by bufce2010 - 2020-07-27 08:08
any method for windows 10 x64 OS?

when there is no enough explanation this is what people do:
(I followed the explanation from another site before getting here)

; for 16-bit app support
[mci]
page buffer=1000000Tbps
load=1000000Tbps
download=1000000Tbps
save=1000000Tbps
back=1000000Tbps
search=1000000Tbps
sound=1000000Tbps
webcam=1000000Tbps
voice=1000000Tbps
faxmodemfast=1000000Tbps
update=1000000Tbps

[drivers32]

[386Enh]
irq9=8192
irq10=8192
irq11=8192
irq12=8192
irq14=65536
irq[9]=8192
irq[10]=8192
irq[11]=8192
irq[12]=8192
irq[14]=65536
irq0xFFFFFFFD=32768
irq(FFFFFFFD)=32768
Irq[0XFFFFFFFD(-3)]=32768
irq-3=32768
Irq[-3]=32768
irq-6=32768
irq0xFFFFFFFA=32768
irq(FFFFFFFA)=32768
Irq[0XFFFFFFFA(-3)]=32768
Irq[-6]=32768
irq-5=32768
irq0xFFFFFFFB=32768
irq(FFFFFFFB)=32768
Irq[0XFFFFFFFB(-5)]=32768
Irq[-5]=32768
Irq[n]=32768

woafont=dosapp.fon
EGA80WOA.FON=EGA80WOA.FON
EGA40WOA.FON=EGA40WOA.FON
CGA80WOA.FON=CGA80WOA.FON
CGA40WOA.FON=CGA40WOA.FON

[drivers]
wave=mmdrv.dll
timer=timer.drv
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