Updating ram & troubleshooting


Posts: 5,746   +14
In the past few days I have noticed many questions from people with memory (RAM) issues. Being that I have ran into similar problems in the past, I am posting this sticky so that FAQs can be answered quickly.

First: Know the types of RAM that your motherboard can take. If not sure Read The F***ing Manual (RTFM), or contact the manufacturer (go to the website or call.). 80% of installation RAM problems are caused by incompatibility. Some motherboards are very picky about what types or brands of RAM they'll take. Asus is one of the motherboards, Dell is another – in addition, Dell uses proprietary architecture in many of their systems so generic RAM or third party RAM will not work in many cases. It PAYS to build your own computer.

CPU-Z is a good program to use to check out your RAM type. It is free, however, it will not NOT tell you what brands your motherboard will take, only the type.

Be aware that identifying programs and/or websites are NOT 100% reliable indicators of what type of RAM you can use. When all else fails RTFM.

NEVER MIX SPEED, TYPES, SIZE, OR BRANDS OF RAM. At best it might work, at worst it won't and you might permanently do some damage. Faster memory mixed with slower will always result in the slowest speed available if it does work (and you're wasting the faster memory speed for nothing.) I repeat again, do NOT mix types of RAM, use the proper type for the proper system. Failing to follow this most basic of instructions will cause 98% of problems later on.

DO NOT OVERCLOCK memory. This means do not adjust voltage settings, latencies, or other settings in your BIOS before installation. Increasing voltage is a sure way to burn out your memory early. Leave this stuff for experimenters and those that can afford toasted and burned out components. If you're a newbie or an average joe/jane – LEAVE IT ALONE.

Step 2:

When installing, GROUND YOURSELF and the Computer. Use an anti-static mat and/or wrist strap – available at Radio shack and most electronics stores. Some recommend keeping your computer plugged in the wall for grounding reasons, I do not. Accidentally turning on your computer is a sure way to damage something as well as to shock yourself- so leave it unplugged. You may want to run a thin wire from the case of the computer to a common ground like a cold water pipe. Do not work on a computer in a carpeted room if possible. Turn OFF the computer. I have seen stupid people plug components in when the system was still on. If you're that dumb, don't bother upgrading the system yourself. Read a book about basic computing before attempting operation.

Touch the computer frame and if you can, keep a part of your body in contact with the frame at all times to ensure no static buildup.

Step 3:

Locate your memory slots. Motherboards vary in the number of slots available. Some motherboards, particularly Pentium, require memory upgrades in pairs. Always try to match memory sticks when upgrading for enhanced performance, particularly with DDR RAM.

Step 4:
There are 3 basic types of installation depending on your type of RAM:

When installing SIMMs, most manufacturers require the module to be inserted at a 45 degree angle, then snapped forward to the correct position. Most Pentium systems require matched pairs.

Unlike SIMM, DIMMs may be snapped directly into the socket. Note: Some DIMM sockets have different physical characteristics. If your module doesn't seem to fit, do not force it. You probably have an incompatible type. DDR, DDR2, DDR3 are not interchangable. Use the proper type of RAM. Refer to Step 1.

SODIMM: (Commonly found in laptops)
Insert the module and snap down into position. Some laptops require a single SODIMM module while others require matched pairs.

Put your case back together, and replug everything. Turn on your computer and boot up as normal. Your BIOS should automatically recognize the added memory. If you did it right, you shouldn't have any issues, however.......

if you did it wrong:

1.If you receive an error message or hear a series of beeps when booting, your system may not be recognizing the new memory. Remove and reinstall the modules to make sure they are seated securely in their sockets.

2.Make sure that your new memory is the same type as your old memory. (i.e. FPM,EDO,SDRAM,parity/non-parity/ECC). Using EDO or SDRAM in a system that does not support it will not work, often resulting in a blank screen or no POST (Power On Self Test), or a BIOS/CMOS setup error. DDR and DDR2, DDR3 etc.... are NOT interchangable.

3.Fill your slots with the largest density (put the largest module in blank 0), the second largest in bank 1, and so on. Remember, it is always advisable to have all modules the same size.

4.If your module will not fit, it may be incompatible. There are different notches for for 3.3V, 5V, buffered, and unbuffered memory modules. Make sure your module is oriented in the right direction also.

5.If your system still won't boot up, check your other computer connections internally with the power off. You may have bumped or jostled another component accidentally.

6.If you can boot up and get other errors, run MEMTEST86+ from a DOS bootable floppy disk. It is not advisable to run a computer without a floppy drive. Floppy drives are still required for hardware diagnosis and BIOS updates, this is a leftover architecture requirement from the early days of computing. All Intel based computers (to include AMD) have 8088 architecture at their core for basic operation. IF you are using DOS 6.22 and earlier and are getting memory errors, consider running memmaker to re-configure your memory settings.

7.If you get a memory mixmatch error, follow the prompts to enter setup, then select save and exit. (This is not an error – some systems must do this to update their CMOS settings.)

8.If your system is only recognizing half of a new module's memory, contact the module manufacturer tech support.

9.Recognize that adding TOO much memory (rare) may not be recognized by your operating system. Every operating system has an upper limit. Windows XP has an upper limit of 4 Megabytes. Older versions of Windows are less.

10.When all else fails, RTFM.


Posts: 21,238   +17
This thread is a copy of this thread HERE, minus the posts.

I think it deserves it`s place in our Guides and Solved Issues forum.

If you have any questions pertaining to this thread, please post in the original thread above.

Regards Howard :)


Posts: 613   +2
A correction kind sirs: XP has an upper limit of 4 GIGAbytes.

DOS could handle 4mb. I still remember the fit my dad threw when I said I wanted that to run DOOM I. :)


Posts: 5,746   +14
Understand there are new types of ram coming out all the type.
DDR, DDR2, and DDR3 are NOT interchangable. Use the right kind of ram for the right motherboard, again, RTFM.
Not memory issue

Thanks for the reply from all the repliers; however it turn out to be a bad disc not memory. By the way I did read the manual.


Posts: 232   +2
Well my manual doesnt actually say anything except it takes DDR and only supports up to 4gig. I have to look up chipset to discover i couldnt support High Density Ram
Memory / mobo ISSUE

One of my memory slots doesn't seem to work. When I insert a working module in that slot, the computer powers on but doesn't boot at all. I want to run on Dual Channel, is there anything I can do to fix this slot, well if the slot is messed up what led to this problem. Am running a Intel D865GSA motherboard, kindly let me know if there is anything that can be done.


Posts: 867   +13
palazzi are all your memory DIMMs exactly the same? If they are not the same then you could have memory compatibility problems. If they are the same then DIMM slots break because people break them by using excessive force to set memory and because stuff breaks through normal usage.


Posts: 5,746   +14
MEMTEST 86+ is now available for booting off a CD rom as well as a floppy. In order to make a bootable CD rom, you will need to download the program and create a bootable ISO file on your CD. Memtest 86+ can be downloaded from http://www.memtest86.com/

This however, is not the best or preferred method. While floppies may seem archaic, it still is the best method for diagnosing ram issues as you are dealing with root, fundamental operations.

MEMTEST 86+ is a wonderful diagnostic tool and certainly worth the miniscule donation the authors request. Many problems can be discovered with this tool. I consider it essential.

The old rules of not mixing ram types still applies, even with newer modules. While timings and speeds have gotten faster and somewhat more flexible over the last couple of years since the original writing of this guide, the fundamentals still remain the same.

DDR1, DDR2, DDR3 have come into play, and essentially they are just faster flavors. And no - they're not interchangeable. The old rules still apply, and and the mixing of ram types and speeds are never advised (although it will work sometimes. - and if it does, it will run at the lowest ram bank setting.)

Gamers and overclockers will note that with faster and high end ram, tolerances for ram timings is more tight with little wiggle room for error. Again, I do not recommend playing with timings, unless you have $ to burn. RAM tends to be less forgiving with over-voltages than does other components. Cooling is a must and really consider how your rig will be cooled as well as the ram sticks themselves.

Again the old rules of knowing what ram types and speeds and models your motherboard will accept applies. It has been discussed ad naseum here on techspot --that new builders suddenly find that their rig won't work, because they didn't RTFM and therefore used a brand or type that the motherboard is incompatible with. When buying a motherboard, Read the F*ing Manual! (RTFM!) You'll save yourself a lot of heartache.

A question that often comes up with noobs, is how much do I need? Well factor at least 1gb for XP and 2- 4gb for Vista 32 bit. 64bit OSes can tackle a whole lot more and 8gb or more is recommended.

Below is table of common RAM:

Memory Module and Bus Standards/Bandwith
Module Standard Module Format Chip Type Clock Speed (MHz) Cycles per Clock Bus Speed (MT/s) Bus Width (Bytes) Transfer Rate (MBps)
FPM SIMM 60ns 22 1 22 8 177
EDO SIMM 60ns 33 1 33 8 266
PC66 SDR DIMM 10ns 66 1 66 8 533
PC100 SDR DIMM 8ns 100 1 100 8 800
PC133 SDR DIMM 7/7.5ns 133 1 133 8 1,066
PC1600 DDR DIMM DDR200 100 2 200 8 1,600
PC2100 DDR DIMM DDR266 133 2 266 8 2,133
PC2400 DDR DIMM DDR300 150 2 300 8 2,400
PC2700 DDR DIMM DDR333 166 2 333 8 2,667
PC3000 DDR DIMM DDR366 183 2 366 8 2,933
PC3200 DDR DIMM DDR400 200 2 400 8 3,200
PC3500 DDR DIMM DDR433 216 2 433 8 3,466
PC3700 DDR DIMM DDR466 233 2 466 8 3,733
PC4000 DDR DIMM DDR500 250 2 500 8 4,000
PC4200 DDR DIMM DDR533 266 2 533 8 4,266
PC2-3200 DDR2 DIMM DDR2-400 200 2 400 8 3,200
PC2-4200 DDR2 DIMM DDR2-533 266 2 533 8 4,266
PC2-5300 DDR2 DIMM DDR2-667 333 2 667 8 5,333
PC2-6000 DDR2 DIMM DDR2-750 375 2 750 8 6,000
PC2-6400 DDR2 DIMM DDR2-800 400 2 800 8 6,400
PC2-7200 DDR2 DIMM DDR2-900 450 2 900 8 7,200
PC2-8000 DDR2 DIMM DDR2-1000 500 2 1000 8 8,000
RIMM1200 RIMM-16 PC600 300 2 600 2 1,200
RIMM1400 RIMM-16 PC700 350 2 700 2 1,400
RIMM1600 RIMM-16 PC800 400 2 800 2 1,600
RIMM2100 RIMM-16 PC1066 533 2 1066 2 2,133
RIMM2400 RIMM-16 PC1200 600 2 1200 2 2,400
RIMM3200 RIMM-32 PC800 400 2 800 4 3,200
RIMM4200 RIMM-32 PC1066 533 2 1066 4 4,266
RIMM4800 RIMM-32 PC1200 600 2 1200 4 4,800