June 23, 2000

Window Manager, Brian Livingston

Improve the speed of Web pages, video, and other Net transfers in Windows 2000 and 9x

READERS JAMES BLIESE and Ron Houtman report they're getting greater performance out of their NICs (network interface cards). This translates into faster Web downloads if your corporate Internet access or cable modem/DSL router runs through your NIC.

The trick relates to both Windows 9x and Windows 2000, although there are different methods to use with each operating system. Allow me to explain.

Both Bliese and Houtman independently learned of an obscure setting in Windows 9x that sets aside some of your RAM to buffer your network card.

This acts in somewhat the same way a disk cache works to speed up access to your disk files. In some cases, the setting can also assist devices other than NICs, if they use an IRQ (interrupt request line). For example, a PCI-based network card may share an IRQ with other boards in your system.

By making more RAM available to the IRQ used by your network card, transfers can move in greater quantities. This improves throughput 10 percent or more in some cases. Web pages should display faster, and streaming video should be smoother.

The tweak can be especially helpful for PCs with 500MHz CPUs or slower, or with 128MB of RAM or less. This can add life to older machines that are primarily used to access Web sites.

The steps I describe below devote 4MB of RAM to the IRQ used by your NIC. If your PC is particularly short of RAM (32MB or less), this can take memory away from applications, slowing down your overall performance. But if you have more than 32MB of RAM, the trade-off should be worth it for you.

Step 1. First you need to determine the IRQ used by your NIC. In Windows 9x, open the System control panel and select the Device Manager. Double-click the Computer icon. Under the View Resources tab, select IRQ and note the number(s) used by your NIC(s). (PCI-based network cards often use IRQ 9, but it may be a different number.) Close the control panel.

Step 2. You now need to edit a line into your System.ini file. That's right -- Windows 9x gets this setting out of the old text file we learned to love in Windows 3.x. Click Start, Run, type Sysedit.exe,and click OK. In the System.ini window, add the following line anywhere in the section headed [386enh]: Irq9=4096

This adds a buffer of 4096KB (4MB) to IRQ 9. If your NIC is on a different interrupt, change the label to Irq12 or whatever the correct number is.

If you have two NICs, use two separate lines to buffer them both. Exit Sysedit, saving your changes, and restart Windows 9x for the change to take effect.

That's it. If you ever change the IRQ used by your NIC, remember to change the setting in System.ini at the same time.

If you ever want to go back to the default value, simply remove any lines you inserted into System.ini and restart Windows.

The effect is described in more detail by Speedguide at www.speedguide.net/Cable_modems/cable_irq.shtml (you must type an uppercase "C" in this address). Speedguide is sponsored by U.S. Interconn, a Florida-based technical company recommended on Microsoft's TechNet resource lists. (Go to www.microsoft.com/technet/win98 or /win2000, then click Web Sites in the right-hand column to see this and other resources.)

The above procedure should not be used under Windows 2000, which handles networking differently than does Win 9x.

Even with its networking enhancements, however, Windows 2000 is designed for a wide range of users and may not be optimized for broadband communications in your particular system.

Speedguide recommends that you add some settings to the Windows 2000 Registry to control the TCP Window. This is a memory buffer for Internet transfers. Unlike Windows NT 4.0, which limited the buffer to 64KB, Windows 2000 is optimized when set to approximately 364KB.

If you don't like editing the Registry, Speedguide provides small files you can download to make the changes for you and undo them later if you wish.

To make the Windows 2000 changes, go to www.speedguide.net/Cable_modems/cable_reg_win2k.shtml (remember the capital "C"). For more information, read the Related Links at the bottom of each page.

Readers Bliese and Houtman will receive free copies of Windows 98 Secrets for being the first to send in these tips.