10 Windows speed tips that don't work

28th Apr 2010 | 11:45

10 Windows speed tips that don't work

Tweaks that do nothing, or could even slow your PC down

10 Windows speed-up myths to avoid

If your PC seems to have slowed down recently, then there's plenty of help to be found online.

A few minutes at Google will turn up hundreds of speed-up guides and tweaking tools, each promising that they can revitalise your system.

And that would be fine, if it wasn't for the fact that many of their tweaks are obsolete, some are urban myths and have never worked, and a few will even cut your performance.

Identifying the dubious tips can be difficult, though, so we've got you off to a head start by listing our top 10.

Despite some of them not doing anything since Windows 98, and others being utterly useless on all versions of Windows, most have regularly appeared in speed-up guides and tools across the web. But, as you'll see, they're all best avoided, so you can focus your attention on the speed-up tweaks that actually deliver.

1. Always unload DLLs

One of the most common speed-up tips covers Windows' use of DLLs. When an application closes down, it's claimed, the DLLs it was using remain in memory for a while, just in case the program is restarted. And so, over time, the system can be wasting a considerable amount of RAM.

However, if you browse to HKEY_LOCAL_MACHINE\Software\Microsoft\Windows\CurrentVersion\Explorer, add a DWORD value called AlwaysUnloadDLL and set it to 1 then you can force Windows to remove the DLLs immediately, freeing up valuable resources.

One immediate problem with this tip is that it's really just turning off a caching system. If Windows keeps DLLs in RAM, then they'll be immediately available for the next application that needs them. Disable this and they'll have to be reloaded from your hard drive, so in some situations the tweak might slow you down.

Fortunately, this is an academic point. A Microsoft document on the AlwaysUnloadDLL Registry key makes it clear that this applies only to Explorer extensions, not all DLLs. And it only works "for operating systems prior to Windows 2000".

2. Boot Vista faster

Vista can take a very long time to load, so it's not surprising that many people leapt at the chance to improve the situation. And it seemed very easy.

The problem, supposedly, was that Vista only used one core during the boot process. If you launched MSCONFIG.EXE, clicked Boot > Advanced Options, checked "Number of processors" and set them to the highest available number, your system would begin to run more quickly.

But, unfortunately, it doesn't. MSCONFIG is actually just setting boot switches that have been around for years (there's a sample list here). But these are included for troubleshooting purposes. If you've old programs that can't run on multicore CPUs, for instance, or one core is faulty, then setting "number of cores" to 1 will disable the other CPUs and perhaps fix the problem.

If you don't set a reduced value, though, Windows will itself detect and use however many cores you have. This tweak doesn't change any of that, and whether it's applied or not, your PC will boot just as it always did.


NO CHANGE:Increasing MSConfig's "Number of processors" setting won't improve your boot time, unfortunately

3. XP and QoS

Long ago it was claimed that Windows XP always reserved 20% of your internet bandwidth for its QoS (Quality of Service) scheme, and so turning this off via GPEdit.msc would make a real difference to download speeds. As per usual, though, this isn't quite true.

Microsoft pointed out that "One hundred percent of the network bandwidth is available to be shared by all programs unless a program specifically requests priority bandwidth. This "reserved" bandwidth is still available to other programs unless the requesting program is sending data"

In other words, if, say, you're using a VoIP tool, and it understands QoS, then it would be able to have priority over 20% of your bandwidth, ensuring you'd always have decent sound quality.

But if you weren't making an internet call then the bandwidth could be used by anything else. And if you were on the phone, then QoS would be helpful - turning it off with this tweak could only have an adverse effect on your system.


DON'T DO IT:Windows XP doesn't always grab 20% of your internet bandwidth - turning off QoS may cause more problems than it solves

4. Level 2 Cache

On some PCs, we've read, Windows doesn't recognise systems Level 2 Cache (a storage area used to improve your system performance). But this is easy to fix.

First launch REGEDIT, go to HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Session Manager\Memory Management, and create a DWORD value called SecondLevelDataCache. Set this to the appropriate value for your CPU, reboot, and that's it - immediate increase in speed.

Sounds good, until you take a look at what Microsoft has to say on this topic. And it turns out the setting only applies to Windows NT, and CPUs that have direct-mapped L2 caches.

If your PC has a Pentium II or later then this tweak will do nothing at all.

5. Clear the Prefetch folder

As Windows boots it monitors the files that are needed, storing this data on your hard drive (the \Windows\Prefetch folder). When you next boot this information is used to load the data your system requires ahead of time, and more efficiently, making for a faster boot.

Some speed-up guides don't quite see it this way, though. The Prefetch gets too big, they say, stores too much information, and deleting its contents occasionally can actually speed up your system.

We still regularly see tweaking programs that will automate this for you, but the bad news is that it's entirely counter-productive. Pre-fetching is a good thing, and deleting the folder will only slow you down. Here's Microsoft's Ryan Myers:

"it is a bad idea to periodically clean out that folder as some tech sites suggest. For one thing, XP will just re-create that data anyways; secondly, it trims the files anyways if there's ever more than 128 of them so that it doesn't needlessly consume space. So not only is deleting the directory totally unnecessary, but you're also putting a temporary dent in your PC's performance."

Windows tweaking

BAD IDEA:Despite what some tweaking tools say, emptying the prefetch folder won't improve performance

USB polling, TCP offloading and more

6. USB polling

Some PC tweaking guides complain that Windows polls your USB controller every millisecond, cutting your performance and preventing laptop CPUs from entering the C3 power-saving state.

But, they say, if you go to HKEY_LOCAL_MACHINE\System\CurrentControlSet\Services\Class\Usb\0000, create a DWORD value called IdleEnable and set it to 1, then Windows will increase the polling interval to 5ms and all will be well.

Are they right? To an extent: Microsoft does have a support document describing this Registry key and the core problem. But it says it applies to Windows 98, Me and 2000 Server SP2. Any performance difference it makes here is likely to be minimal, and there's no reference to it working on Windows XP or later, at all.

7. TCP offloading

Some of the tasks involved in sending data across your network can in many cases be carried out by the CPU on your network adapter, says another tweak, and enabling this will improve performance. Just go to HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\Tcpip\Parameters, create a new DWORD value called DisableTaskOffload and set it to 0.

The problem here? Windows generally enables offloading automatically already. This Registry setting, as its name suggests, exists to allow you to turn the offloading feature off, for network troubleshooting. A Microsoft document on TCP/IP Registry settings confirms that its default setting is already 0, enabling offloading, and so manually adding the value yourself won't change anything.

What's more, TCP Offloading may not always be a great idea. A recent blog post from one of Microsoft's support teams reported they'd spent hundreds of hours on cases involving offloading, and details one where the answer to a performance problem was to turn it off.

8. ConservativeSwapfileUsage=1

Windows will sometimes use the swap file before it needs to do so, we've sometimes read, forcing data out of fast RAM and onto your slow hard drive unnecessarily. But, so the story goes, by adding the line ConservativeSwapfileUsage=1 to the [386enh] section of your System.ini file then the problem will be solved.

Of course it's not quite as simple as that. A Microsoft document explains that enabling this setting doesn't improve speeds, rather it comes at "some cost in overall system performance". Not that it matters to most people, because the document refers to its use in Windows 95 and 98 only - the setting will have no effect on any later version of the operating system.

9. LargeSystemCache

One common Windows speed-up recommendation is that you should increase the memory for file system caching. Just point REGEDIT at HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Session Manager\Memory Management, create a DWORD value called LargeSystemCache (if it doesn't already exist) and set it to 0.

The first question to ask here is: why? Giving more memory to the file cache means less RAM for everything else, after all. How can you be sure that you'll benefit?

And sure enough, if you look at Microsoft's documentation then there are plenty of warnings. This setting is "designed for use with Windows server products that act as servers", they say, and "is not designed for everyday desktop use".

Another Microsoft document explains the setting specifies that "the system favour the system-cache working set rather than the processes working set." That is, Windows memory demands will take priority over your own applications.

If you apply this tweak to a regular edition of Windows, on a PC that rarely runs applications because you're using it as a network server, then it may help. If you're using it on a normal desktop, though, there's a strong chance that you'll actually be reducing your system's performance.

10. IRQ8Priority

An Interrupt Request (IRQ) is a signal used by devices to grab the attention of your CPU. A common speed-up tweak says you can improve your PCs performance by changing the priority of some of these IRQs, particularly #8, the system clock. And to do this you must point REGEDIT at HKEY_LOCAL_MACHINE\SystemCurrentControlSetControlPriorityControl, create a new DWORD value called IRQ8Priority and set it to 1 (for the highest priority).

There are problems with this idea, though.

Like, it doesn't make any sense: there's no reason to believe that somehow boosting the priority of the system clock would help your system speed (and no-one suggesting this ever offers an explanation).

And we couldn't find a single reference to the setting on Microsoft's site.

Still, we couldn't find anything from Microsoft debunking the tip, either, so we decided to try it out for ourselves. We benchmarked a Windows Vista PC using Passmark PerformanceTest, and it scored 756.0.

We applied the IRQ8Priority tweak, rebooted, ran PerformanceTest again and scored: 748.1, fractionally slower. It hadn't really cut our performance, this was within the benchmark's margin of error, but it hadn't improved our system speeds, either. Like so many PC optimisation tweaks, IRQ8Priority turned out to do nothing useful at all.


POINTLESS: Benchmarking our test PC showed the IRQ8Priority tweak had no effect whatsoever


Liked this? Then check out 50 expert tips to make your PC faster

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