The following is a list of XP tweaks that either do not work, do not work as advertised, or that are better left alone. Many of these once worked in some version of Windows and virtually every other tweak guide and program uses these tweaks.
Over time and through exhaustive research we have come up with the conclusions below. We will give you what is false and what is a right way.
Memory Optimizers
They claim "Increasing the amount of available RAM improves performance". However, the only thing that these programs can do is harm real system performance.
Although gaining more available memory might seem beneficial, it isn't. As RAM Optimizers force the available-memory counter up, they force other processes' data and code out of memory. However, because virtual memory masks the layout of physical memory from processes, processes can't directly benefit from having virtual memory backed by contiguous physical memory. As processes execute and undergo working-set trimming and growth, their virtual-memory-to-physical-memory mappings will become fragmented despite the availability of contiguous memory.
Prefetch Parameters
The Prefetcher component in Windows XP is part of the Memory Manager, and helps to shorten the amount of time it takes to start Windows and programs. You may want to disable this component for troubleshooting scenarios or in lab environments. The following list describes the different possible values for the Enable Prefetcher key.
0 = Disabled
1 = Application launch prefetching enabled
2 = Boot prefetching enabled
3 = Applaunch & Boot enabled
By default the Prefetcher is set to a Value of 3 in Windows XP. Values such as 4, 5, 6 etc. do not exist and are thus useless. The default value is already optimal for maximum performance.
L2 Cache Tweak
Many tweaks claim "Adjusting the SecondLevelDataCache Registry value to match your CPU's L2 Cache size will improve performance".
Actually Windows will use the HAL (Hardware Abstraction Layer) for retrieval of the L2 cache size automatically on boot up. The HAL is able to retrieve the L2 cache size from any CPU using the set-associative cache design (Pentium II or newer).
Always Unload Dll's
The first and most important point is, no evidence shows that this setting works in Windows 2000/XP. In fact, the official Microsoft technical documentation clearly and unequivocally states. For operating systems prior to Windows 2000, you can shorten the inactive period by adding the following information to the registry.
[HKEY_LOCAL_MACHINE\ Software\ Microsoft\Windows\CurrentVersion\ Explorer\AlwaysUnloadDll]
Windows 2000/XP uses a complex and efficient process to manage memory operations. It keeps the DLL loaded in case you need it again. If this tweak actually did work, you have hurt your overall performance because you unloaded a DLL when it didn't need to be and caused the system to have to load it again when called upon.
Set Irq Priority
This "tweak" can be found in most XP all-in-one tweaking applications. This is a perfect example of why they are not recommended. Adjusting the Priority of IRQs especially IRQ 8 will improve system performance" -
[HKEY_LOCAL_MACHINE\System\CurrentControlSet\Control\PriorityControl]
"IRQ8Priority"=dword:00000001
However, IRQs don't even HAVE a concept of "priority" in the NT family. The NT family of OSes doesn't even use the real-time clock (IRQ 8) for time keeping in the first place!
Large System Cache
Most tweaking applications think Enable Large System cache will increase I/O speed of the file system -
[HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Session Manager\Memory Management]
"LargeSystemCache"=dword:000000001
This setting is also achieved by going to Start > Settings > Control Panel > System > Advanced > Performance Settings > Advanced > Memory usage = System Cache.
Under XP this tweak could be of some value under various odd circumstances. However, it causes problems with many drivers/hardware/applications. This tweak is really designed for machines running as a server. If you use this tweak and have problems don't be whining at the driver/application writers for writing code that takes advantage of the way XP uses memory. They didn't ask you to turn your machine into a server.
I/O PageLockLimit
The tweak below are always considered as an effective way to boost your harddisk buffer.
[HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Session Manager\Memory Management]
"IOPageLockLimit"=dword: somevalue
Indeed, it does absolutely nothing in Windows 2000 Service Pack 1 and up, and absolutely nothing in Windows XP.
FIFO Buffer
This is a new myth about tweaking Windows. It says that Increase the FIFO buffer can greatly boost your Windows system
[HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\Serial]
"RxFIFO" = dword: &H10
It is real a fake, since the registry key "Serial" claims that it is only related with "Serial port". How can "Serial port" work on the whole performance of Windows?
PageFile Size Setting
Note that the common myth about the pagefile being .1.5 x RAM. or some other multiple is quite clearly counterintuitive. Consider the situation where you only have 128MB of RAM: setting the maximum pagefile size to 1.5 x 128MB = 192MB + 128MB = 320MB of total available memory for Windows XP which is obviously not going to give you enough memory for modern games and applications. Remember, it is about how much total memory (RAM + Pagefile) that should be made available for Windows to operate efficiently.
Taken from Intelli HyperSpeed 2005 Help File
N.B. Intelli HyperSpeed 05 is a tweaking software.Home Page is http://www.iobit.com/
Over time and through exhaustive research we have come up with the conclusions below. We will give you what is false and what is a right way.
Memory Optimizers
They claim "Increasing the amount of available RAM improves performance". However, the only thing that these programs can do is harm real system performance.
Although gaining more available memory might seem beneficial, it isn't. As RAM Optimizers force the available-memory counter up, they force other processes' data and code out of memory. However, because virtual memory masks the layout of physical memory from processes, processes can't directly benefit from having virtual memory backed by contiguous physical memory. As processes execute and undergo working-set trimming and growth, their virtual-memory-to-physical-memory mappings will become fragmented despite the availability of contiguous memory.
Prefetch Parameters
The Prefetcher component in Windows XP is part of the Memory Manager, and helps to shorten the amount of time it takes to start Windows and programs. You may want to disable this component for troubleshooting scenarios or in lab environments. The following list describes the different possible values for the Enable Prefetcher key.
0 = Disabled
1 = Application launch prefetching enabled
2 = Boot prefetching enabled
3 = Applaunch & Boot enabled
By default the Prefetcher is set to a Value of 3 in Windows XP. Values such as 4, 5, 6 etc. do not exist and are thus useless. The default value is already optimal for maximum performance.
L2 Cache Tweak
Many tweaks claim "Adjusting the SecondLevelDataCache Registry value to match your CPU's L2 Cache size will improve performance".
Actually Windows will use the HAL (Hardware Abstraction Layer) for retrieval of the L2 cache size automatically on boot up. The HAL is able to retrieve the L2 cache size from any CPU using the set-associative cache design (Pentium II or newer).
Always Unload Dll's
The first and most important point is, no evidence shows that this setting works in Windows 2000/XP. In fact, the official Microsoft technical documentation clearly and unequivocally states. For operating systems prior to Windows 2000, you can shorten the inactive period by adding the following information to the registry.
[HKEY_LOCAL_MACHINE\ Software\ Microsoft\Windows\CurrentVersion\ Explorer\AlwaysUnloadDll]
Windows 2000/XP uses a complex and efficient process to manage memory operations. It keeps the DLL loaded in case you need it again. If this tweak actually did work, you have hurt your overall performance because you unloaded a DLL when it didn't need to be and caused the system to have to load it again when called upon.
Set Irq Priority
This "tweak" can be found in most XP all-in-one tweaking applications. This is a perfect example of why they are not recommended. Adjusting the Priority of IRQs especially IRQ 8 will improve system performance" -
[HKEY_LOCAL_MACHINE\System\CurrentControlSet\Control\PriorityControl]
"IRQ8Priority"=dword:00000001
However, IRQs don't even HAVE a concept of "priority" in the NT family. The NT family of OSes doesn't even use the real-time clock (IRQ 8) for time keeping in the first place!
Large System Cache
Most tweaking applications think Enable Large System cache will increase I/O speed of the file system -
[HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Session Manager\Memory Management]
"LargeSystemCache"=dword:000000001
This setting is also achieved by going to Start > Settings > Control Panel > System > Advanced > Performance Settings > Advanced > Memory usage = System Cache.
Under XP this tweak could be of some value under various odd circumstances. However, it causes problems with many drivers/hardware/applications. This tweak is really designed for machines running as a server. If you use this tweak and have problems don't be whining at the driver/application writers for writing code that takes advantage of the way XP uses memory. They didn't ask you to turn your machine into a server.
I/O PageLockLimit
The tweak below are always considered as an effective way to boost your harddisk buffer.
[HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Session Manager\Memory Management]
"IOPageLockLimit"=dword: somevalue
Indeed, it does absolutely nothing in Windows 2000 Service Pack 1 and up, and absolutely nothing in Windows XP.
FIFO Buffer
This is a new myth about tweaking Windows. It says that Increase the FIFO buffer can greatly boost your Windows system
[HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\Serial]
"RxFIFO" = dword: &H10
It is real a fake, since the registry key "Serial" claims that it is only related with "Serial port". How can "Serial port" work on the whole performance of Windows?
PageFile Size Setting
Note that the common myth about the pagefile being .1.5 x RAM. or some other multiple is quite clearly counterintuitive. Consider the situation where you only have 128MB of RAM: setting the maximum pagefile size to 1.5 x 128MB = 192MB + 128MB = 320MB of total available memory for Windows XP which is obviously not going to give you enough memory for modern games and applications. Remember, it is about how much total memory (RAM + Pagefile) that should be made available for Windows to operate efficiently.
Taken from Intelli HyperSpeed 2005 Help File
N.B. Intelli HyperSpeed 05 is a tweaking software.Home Page is http://www.iobit.com/
