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Why is my computer slow and why is there a yellow ! in device manager

Posted By : of Data Doctors on August 22, 1999

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I really don't know too much about computers, but I have taken mine in several times to get it to be faster. Got a new modem and motherboard ...and it is still slow. I delete my temp files and , I don't know if it makes much of a difference but what do I need to do to make it faster .oh another thing i noticed is when i right click on my computer &look under device manager there is a yellow! that says via bus master pci ide controller (ulra dma )?????????????

This question was answered on August 22, 1999. Much of the information contained herein may have changed since posting.


This information was found on the web site of PC Guide which explains the concept of bus mastering that you might have applied to your hard drive, and maybe it wasn't configured properly or your bios set up is not configured properly , and some of the reasons as to why your computer has been slow.

The PCI bus also allows you to set up compatible IDE/ATA hard disk drives to be bus masters Under the correct conditions this can increase performance over the use of PIO modes, which are the default way that IDE/ATA hard disks transfer data to and from the system When PCI bus mastering is used, IDE/ATA devices use DMA modes to transfer data instead of PIO; IDE/ATA DMA modes are described in detail here.

Since this capability was made available to newer machines, it has been one of the most talked about (and most misunderstood) functions of the modern PC There is a lot of confusion amongst PC users about what PCI IDE bus mastering does and how it works In particular, there are a lot of misconceptions about its performance advantages In addition, there have been a lot of problems with compatibility in getting this new technology to work.

IDE bus mastering requires all of the following in order to function at all:

Bus Mastering Capable System Hardware: This includes the motherboard, chipset, bus and BIOS Most newer motherboards using the Intel 430 Pentium chipset family (FX, HX, VX, TX) or the Intel 440FX Pentium Pro chipset, will support bus mastering IDE

Bus Mastering Hard Disk: Normally this means that the drive must be capable of at least multiword DMA mode 2 transfers All Ultra ATA hard disks also support bus mastering

32-Bit Multitasking Operating System: This means usually Windows NT, Windows 95, Linux, or similar (but see below for caveats.)

Bus Mastering Drivers: A special driver must be provided to the operating system to enable bus mastering to work

Getting this all set up can be a great deal of work In particular, the following are common problems encountered when trying to set up bus mastering:

Driver bugs and incompatibility issues, especially with older drivers that are "generic" and not tuned to a particular motherboard

Older hard disk drives not working properly

Problems with dissimilar drives connected to the same IDE channel as master and slave

Problems when using a CD-ROM drive alone on an IDE channel without a hard drive

Bus mastering drivers that don't work on certain motherboards; also, some motherboards or systems just will not work with bus mastering at all

Assuming that you get bus mastering IDE to work, you will see improvement if you are using a true multi-tasking operating system, and you are running multiple applications that are disk-access-intensive This would not generally include most regular Windows 95 users, for example Bus mastering IDE will not help at all in the following situations:

It will not make that 100 MB transfer from C: to D: that you are sitting and watching go much faster at all

It will not speed up DOS games

It will not make applications load more quickly (unless you somehow are loading more than one at a time)

It will not speed up single applications

Especially: IDE bus mastering will not really speed up Windows 95 in general Windows 95 does not do "true" multitasking and in many cases the processor will be held up waiting for the transfer to complete even if bus mastering is employed So even though the processor in theory is freed up to do other things, it doesn't really do other things Also, most people multitask by switching between applications that are open, but rarely have anything running in two or more simultaneously.

This is the part that will explain to you some of the reasons as to why a computer can be slow.

Explanation: You have been using your PC for a while, but you notice now that it is running slower than it used to run, or slower than it should be running.

Diagnosis: There are two generic causes for this problem: either something has changed gradually over time to cause performance to degrade, or there has been an abrupt hardware or software change that is responsible for reduced performance There are a number of different situations that can be responsible for the system performance changing

Recommendation: Try some of the suggestions below

Scan the system for viruses, as they can slow the system down

Have you recently add more memory to your system? Do you now have more than 64 MB of system RAM? If so, and you notice a slowdown, it may be because your PC does not support caching of more than 64 MB of system memory This will cause performance to be degraded when accessing the uncached memory

Check the processor to make sure it is not overheating, and make sure the CPU fan is still running Some CPUs, especially OverDrive processors, will intentionally slow the CPU down if they detect a failed fan, in order to prevent heat buildup

Double-check all BIOS options to make sure nothing has been changed from what it should be Look at cache and memory timings, and hard disk modes Verify against your last BIOS settings backup Sometimes people accidentally change a parameter when they are trying to modify something else in the BIOS Viruses can also change BIOS settings, rarely

On an older machine with a functional turbo switch, make sure it is pressed in and the turbo light is on If you find yourself frequently accidentally disabling turbo and seeing your PC go into glacier mode, as a result, consider disabling the switch See here for details

Do you see the hard disk light flickering a lot when you load a lot of programs into Windows? Does your machine not have a lot of memory? The PC is probably thrashing

Try defragmenting the hard disk If you have not defragmented in a while, file fragmentation can lead to reduced performance

Check the free space on your hard disk, especially the C: volume An overly-full hard disk can reduce performance In particular, if you have set Windows 95 to dynamically resize the swap file, and you let the volume where the swap file resides get too full, Windows 95 will shrink the size of the swap file and this can cause problems

Try updating your Windows drivers

Look in the C:\Windows\Start Menu\Programs\Startup folder and see how many programs are starting up automatically when you boot up the machine See if you can delete some of them.

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Posted by of Data Doctors on August 22, 1999

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