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Upgrade 101 - 9 - Processor upgradesToronto Star Upgrade 101 series - part 9 Due to its length, the published article ran in two parts (9a and 9b), first on November 18/99, then on November 25. In this online version, both parts are together as originally writtenCopyright ©, Myles White, 1999 Preparation and Precautions (READ THIS FIRST)
Hang onto your hair, folks. In this, the ninth of our 10-part series on upgrading your computer, we're about to journey into wild country. This week, we'll discuss replacing your system's central processor. In part 10, it's motherboards (otherwise known as the mother of all upgrades). This is a level 4 task, which means that it may present some extra difficulties, can be just a little scary, entails some risks, and there's no guarantee that it will work the way you expect it to work (or, for that matter, work at all). Tools required include the standard set - multiheaded screwdriver for opening the case and possibly prying up the old processor, long tweezers or needle-nosed plyers for dropped parts, and your favourite method for dispatching the static electricity carried by your body. Static is a particular enemy here, so it's a good idea to review our preparations and precautions (see above). There are a couple of reasons why you may consider a processor upgrade. The most obvious is that you want your computer to run faster without going to the expense and hassle of buying a new computer or performing a total motherboard replacement. Another reason to consider such radical surgery is to get software compatibility you don't have now - for example, upgrading an older Pentium processor to one with the MultiMedia eXtension (MMX) instruction set to support an application that is written to take advantage of it or upgrading to Pentium III for additional multimedia enhancements for the same reasons. There are still a lot of people who have computers based on Intel's 80486 processors (aka "486s") so we'll deal with that group first, then talk to folks with older Pentium systems, and finally discuss options for people with Pentium II- and Celeron-based products. We'll also touch on AMD K6-x systems and the touchy topic of overclocking processors to make them run faster without necessarily replacing the processor at all. Before we get started, though, I want to note something that is going to affect everyone considering any kind of processor upgrade. There is no guarantee that this will work for you. Manufacturers of computers, particularly the multinational name brands, do all manner of proprietary things to their systems that prevent many processor upgrades from working. You really need to work closely with the vendor who is selling you the processor replacement to have even a faint chance that this approach will do you any good at all. When a replacement part manufacturer has a compatibility or incompatibility list at its Web site, believe it. If your system or its motherboard isn't on the compatibility list, don't let your hopes override your judgment. If it's on the incompatible list, try not to convince yourself that they made a mistake. And, simply because a product is mentioned here, that does not mean that I endorse it or suggest it may be suitable for you (so if it doesn't work, please don't yell at me). 486 upgrades
Your 486 processor is a candidate for replacement if your motherboard base speed was 25, 33, or 40 MHz. People with 486 DX50 systems (and 50 MHz motherboards) may be candidates, but only if their motherboards allow them to be turned down to 40 MHz or less. The processors themselves may have been any of the following and at any speed except for the DX50 noted above: 486SX, 486DX, 486SX2, 486DX2. If your system already has a 486DX4/100 processor in it, there's not much point looking for a replacement. None of the parts you can find on the market will improve performance enough to warrant the cost and even those companies still selling the parts acknowledge this.
You can still find the odd Intel DX4 OverDrive processor at used computer stores, swap meets and similar venues. Johnston reports that most of them are OEM (Original Equipment Manufacturer) versions of the product that often come wrapped in tinfoil without a box, documentation, or any clues or assurances to tell you whether it is used or new. The DX4 OverDrive is a special version of the 486 DX4 processor that contains a voltage regulator (required because most 486 processor sockets output 5 volts, while the processor itself is a 3.5 volt part) and a heat sink. Compared to a 486 DX2/66, the part gave me a 50 per cent improvement in both processing speed and video speed when I installed one several years ago. Pentium upgrades
The age of your older Pentium system is going to determine what you can do with it.
Intel advises against using its 200 MHz Pentium MMX OverDrive processor in Socket 5 systems, "unless the system meets the minimum Socket 7 specification," which is fairly hard to determine. It's also a moot point, because the part is out of production and very hard to find. It's a little easier to find Intel's 233 MHz OverDrive, but says Grey-Tech's Johnston, "It's a commodity product selling for around Cdn$100 when you can find it and comes without box, documentation, or warranty." The regular gang of replacement processor companies is in this market, too. PowerLeap and Kingston products incorporate an Intel 233 MHz MMX processor with suitable chip fan and voltage regulator to handle the difference between Pentium and Pentium MMX voltage demands (see more below).
One last note: it may be tempting to avoid these upgrade kits and "OverDrive" processors and simply acquire an Intel MMX processor suitable for your non-MMX Pentium system. Don't bother unless your motherboard manual explicitly tells you that this is possible. The standard Pentium processor socket (whether Socket 5 or 7) outputs 3.5 volts. (The original Pentium 60 and 66 used a 5-volt socket which explains why there are so few alternatives for them.) A Pentium MMX processor, however, is a dual-voltage part, requiring 3.5 volts for input/output operations and 2.8 volts to its core. You need the additional circuitry in the kits/OverDrive models to bridge this difference. At best your new MMX processor won't work if you can't adjust the voltage. At worst, you'll fry it.
AMDWhat about AMD replacements? If you've done even preliminary research into replacing a Pentium MMX processor with something faster than 233 MHz, you'll have heard of AMD's K6, K6-2, and K6-3 (or K6-III) alternatives. And there's a possibility these processors may work in your system - but only if:
K6-2 and K6-3 processors ranging from 75 to 400 MHz are available in the GTA, although the slower models are scarcer than the faster alternatives. An AMD K6-2/380 ("harder to come by," says Grey-Tech's Johnston) retails for around Cdn$89, while a 400 MHz K6-3 is closer to Cdn$100. For those who do not have dual/alterable voltage systems, Powerleap, Kingston, and Evergreen have kits.
Pentium II or Celeron
The good news is that this won't stop you from upgrading to one of the newer and faster Celerons at up to 500 MHz (because they all run on 66 MHz motherboards). If the new Celeron you're eyeing comes in the square "Socket 370" format, you'll also need a special converter board if your motherboard uses Slot 1 (several companies make them and they're widely available).
For the sake of comparison, approximate prices the week of November 8 for various Celeron and Pentium II/III processors (retail, Toronto area, Canadian funds, may vary from vendor to vendor):
This situation will get even more complicated when Intel re-introduces a socket design for many of its newly introduced Coppermine Pentium III processors. For even more enjoyment, it won't be compatible with the Celeron socket, either. Back to topInstallation486 and Pentium Socket 5/7 motherboardsDepending on how old your 486 is, it either has a LIF (light insertion force) or ZIF (zero insertion force) processor socket, or it doesn't. There are some subtle differences between them, but so far as I can determine they're irrelevant unless you're trying to use Intel's Pentium II OverDrive processor for the Pentium Pro's Socket 8 (you can use it if you have a ZIF, but not if you have a LIF). A LIF/ZIF socket is identifiable by the small lever lying along one side. If there is no lever, start looking for a small, flat-bladed screwdriver instead. I know of no Pentium or Pentium MMX or AMD K6 systems that shipped without a LIF/ZIF socket. Take all the appropriate precautions for discharging static. Be particularly diligent in doing this before you touch either your old or new processor.
Open the system case, then find your processor. It's a large, square component which may or may not have a chip fan or heat sink stuck to the top of it. It's usually located to one side of the expansion slots on your motherboard, although in many 486 and early Pentium systems, it may also have been placed between the end of the expansion slots and the front of the board. If it is not visible at all, that means it's probably hidden under the system's power supply or drive cage and some substantial disassembly will be required before you can get at it (and it's why I've elevated this process to a level 4 task). If your processor has a heat sink or chip fan that prevents you from seeing the socket, that will have to come off. Many chip fans slide away from the processor. Occasionally, they're glued to it, and sometimes there's a restraining clip, too, to hold them firmly to the top of the processor. How you get it off may baffle you. The glued-on models often respond to a firm pull straight up, but fighting with the restraining clip can leave you with bruised or skinned knuckles. If getting to the processor defeats you, you're afraid you might break something, and the motherboard manual doesn't provide clues (not unusual), throw yourself on the mercy of whomever is selling you the replacement and ask them to install it for you. Assuming you do get the chip fan/heat sink off, look for the LIF/ZIF lever. If there isn't one, take a small, thin, flat-bladed screwdriver and begin prying the chip up from the socket. Work in small increments, moving around the processor as you pry. If you try to get it out by lifting only one side, you may break or hopelessly bend the processor's pins. (Bad news. If they break off inside the socket. Your system is now toast.) With a LIF/ZIF socket, you merely pull gently but firmly up on the lever. The processor will now lift out of the socket without force. Once the original processor is out, carefully place it to one side. You may have to re-insert it later if the replacement doesn't work or to satisfy someone's tech support department that the problems you now have with your hard drive, CD-ROM drive, operating system or other components really is the fault of the new processor. Have a look at the socket. You'll notice that one corner is at an angle, or that the pattern of holes is different in one corner. That's the "Pin 1" corner of the socket. Now look at your replacement processor and the manual that came with it (hopefully). There should be clues about which corner contains Pin 1. If you can see the surface of the processor, it may have a white dot, a small indentation, or one corner may be at an angle. Can't see anything? Turn it over and examine the pins. Again, the pattern should be different in one corner. Whatever, line it up with the Pin 1 corner of the socket. Place the processor straight down into the socket and seat it as far down into the socket as you can. If the LIF/ZIF lever resists your attempts to put it back down, try pushing down on the processor until it allows you to press the lever down easily. If you have no lever, try to keep the processor going straight down, so you don't bend any pins. Again, get it to seat as far down as you can. Follow the instructions in the replacement processor manual to attach any relevant heat sink or chip fan. When you restart your system, especially if it doesn't restart, the main problem may be that although the processor appears to be firmly mounted, it isn't. Push down some more. If you encounter problems with other hardware or software, don't say I didn't warn you. Please call the processor supplier's tech support; only they and prayer are likely to be able to help you now. Back to topPentium II/Celeron Systems
All Pentium II and III processors using Intel's Single-edged cartridge (SEC) design will fit into Slot 1. So will Celeron processors up to about 333 MHz (after that they tend to come only in the Socket 370 configuration). Pentium II processors at 333 MHz or less and all Celeron processors require a front-side bus (the data pathway from processor to main memory) running at 66 MHz. Pentium II and III processors running at speeds from 350 to 650 MHz require a 100 MHz front-side bus. Pentium III "Coppermine" processors at 687, 700 and 733 MHz need a 133 MHz front-side bus. If you're replacing a Slot 1 Celeron with a Pentium II or Pentium III (assuming your motherboard has a 440BX chipset that will allow it to change speed from 66 to 100 MHz), you may also have to change the "goalpost" retention mechanism that holds the Celeron board in place. Check your motherboard manual because some newer boards shipped with a "universal" mechanism suitable for both. If you do have to replace them and you're lucky, the goalposts are held in place from the top with small screws. Otherwise, you may have to remove your motherboard entirely to get at the bottom of it to push small plastic retainers back through the board. It's tedious and may be another reason to have this done for you.
Once you have the goalpost problem sorted out, removing and replacing the boards is dead simple. Rock the old board gently from end to end while lifting straight up. Slide the new cartridge or circuit board into the slot and push down until it's firmly seated. No fuss, no bother. You should not encounter any particular problems from here on in, but... I mentioned earlier that the "MHz" numbers associated with the internal speed of processors is always a multiple of the motherboard base (or front-side bus) speed. Some motherboards have settings that allow you to adjust the multiplier. If yours does (the manual will tell you), take the required steps to set the multiplier for the new processor. Resist, for now, any temptations you might have to also adjust the front-side bus speed or the multiplier to a figure that's inappropriate for your processor until you've read the next and final section. Overclocking"Overclocking" is a fad that has become a way of life for some keen computer afficionados. Literally it means setting the front-side bus speed and/or multiplier to a value that's higher than the original processor is designed to accommodate. Sometimes it works. Sometimes it results in reduced processor life, damaged expansion cards, or fried processors. When the processor is run at a higher speed than was intended, it gets hotter than intended, so heat dissipation is a major concern. There are numerous Internet Web sites that give exhaustive advice on overclocking and while some of them are keener proponents of the activity than others, every one of them repeats these warnings, sometimes in great and gruesome detail. No conscientious retailer in the GTA recommends it. No computer component manufacturer recommends it. I don't recommend it. What you do is up to you, so long as you understand that the risks are very real. Back to topQuestions?Send them to troubleshooter@computerwriter.com or by fax to 416-425-4644. Many components for this series were supplied by Grey-Tech Computers, Inc., Markham, Ontario www.greytech.com | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
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Back to Upgrade 101 Contents
Let's
get some other things out of the way:
Intel Pentium MMX
If
you have a Celeron system with Socket 370 already on the
motherboard, you have fewer upgrade options. You can upgrade
to a newer, faster Socket 370 Celeron, but, says Grey-Tech's
Adil Sunderji, "There are no converter boards that
allow you to place a Slot 1 cartridge-based processor in a
Socket 370 motherboard. There are only boards allowing you
to put a Socket 370 processor on a Slot 1 motherboard."
Part
10, Processor Replacements