Memory Page

• All programs, instructions, and data must be stored in system memory before the computer can use it.  It will hold recently used programs, instructions, and data in memory if there is room.  This provides quick access (much faster than hard drives) to information.  The more memory you have, the more information you will have fast access to and the better your computer will perform. 

What To Look For:

• First you need to know the type of memory you need.  Some computers still use SIMMs which are an older, slower form of memory (and many more types prior to them).  DIMMs are the newest flavor, most of which are of the SDRAM format.  Currently SDRAM is the most common and the fastest.  If you are purchasing SDRAM memory for a Pentium II 333 computer or earlier, you should get 10 ns SDRAM (or faster so that you can use it with the newer CPUs).  If you are purchasing a new Pentium II that runs on the 100 MHz bus (350 and higher), you need to have the most recent "standard" type of memory called PC100 compliant memory.  This is memory that is "certified" for use on the 100 MHz bus.  Since it is relatively new and in high demand, it is much more expensive than regular SDRAM.  Make sure the memory will work with the motherboard you are getting (or have).  PC133 is a newer type of memory that is designed to run at 133 MHz bus speed for processors like the P3B. 
• Once you have found PC100 memory, you need to look for a few different things IF you think you may overclock (though they will also make your memory more reliable if you aren't).  First is the CAS delay, which will be 2 or 3.  If you want to run at 133, use memory with a CAS (column access strobe) latency of 2.  You also want to look at the ns (nanosecond) rating, but be careful in interpreting it.  Some hardware vendors give a different timing for this value.  At this point in time there isn't any SDRAM less than 8ns, however, faster speeds are being developed.  See AnandTech for a more in-depth discussion. 
• 11/13/99 Update- There are several new types of RAM that I thought I should briefly describe here:
  -Direct Rambus or RDRAM is the high bandwidth, high priced RAM that has Intel's backing to be used with their i820 and future chipsets.  With RAM speeds as high as 800 MHz, this truly does have amazing speed!  Surprisingly though, in benchmarks all this great RAM speed has not offered significant improvements!  With the i820 and the Coppermine CPUs with 256k full speed cache, there may be a larger difference.  RDRAM comes in "RIMMS" that are physically different from DIMMs.  Thus, you can't use RDRAM in your BX chipset motherboards. 
  -PC133 and PC100 memory are about the same, except for speed differences.  This RAM is most common right now, and until RDRAM prices come down, this is all you should consider. 
  -VC133 is "Virtual Channel" PC133 RAM which offers some performance enhancements over traditional PC133 RAM.  Whether or not it will be accepted is still up in the air. 
• 11/13/99 - Recently RAM prices have soared.  This is expected to last a significant amount of time, so don't try to wait it out forever. 

Recommendations:

• 6/16/00 Update -- I'd still suggest using the PC133 memory I recommended below in my last update.  There haven't been a lot of new offerings in memory lately. 
• 4/24/00 Update -- A couple of other PC133 brands to consider are Memory Man's CAS2 PC133 RAM and PNY PC133 RAM, both of which have been tested to run up to 160 MHz bus speed.  I don't suggest trying to run at these high speeds though.  You're not likely to have the memory remain stable for very long at that speed.
  King of the crop in stability goes to Mushkin's PC133 with Mosel Vitalic chips, but the affordability of the others is difficult to pass up.  I still like the Corsair/Micron PC133 because it's fairly low cost and reliable.
• 1/17/00 Update- The Corsair/Micron PC133 RAM is still the best choice for price, speed, and reliability. 
  -- Watch out, RAM prices are expected to go up even further this year.  I'm hoping that won't happen, but it may be wise to buy your RAM now just in case...
• 8/1/99 Update- Corsair/Micron PC133 and EMS PC133 HSDRAM are now available and may be worth the small extra expense.  They're not as expensive as I expected, and they both perform quite well.  I would pick the Corsair over the EMS though.  I have been using the Corsair/Micron PC133 for awhile with great results. 
• 7/1/99 Update- PC133 memory from companies like Samsung is starting to show up.  This is only needed though if you plan on using 133 bus speeds and other high bus speeds.  Also if you're getting the -GH or -G8 memory from mushkin (or other places), I suggest getting the "Samsung Originals" which have the Samsung boards for the chips.  The mushkin brand uses their own boards with Samsung's chips.  The originals are only important though in extreme overclocking. 
• 1/1/99 Samsung makes what I believe to be the highest quality RAM there is.  There are two different types that I would recommend.  For most users, the -GH memory from Samsung should be sufficient.  The newer -G8 memory is even better, particularly for overclocking.  The best place to get either of these is from www.mushkin.com.  All the RAM I buy comes from there. 
  While a lot of other memory has caused problems for me, particularly in motherboards like the Abit BH6, the Samsung RAM has never given me a single problem.  It's solid as a rock as far as RAM goes. 
• Get PC100 memory from a dealer you can trust and make sure it has a CAS latency of 2 (rather than 3).  This memory should have a "-GH" at the end of the numbers on the memory chips themselves.  Examples of memory fitting this description are American Megatrends, Memory Man, and Azzo PC100 SDRAM.  These can be found at American Megatrends, Memory Man, and Ram Warehouse websites. 
• Micron also makes good RAM and has some CAS2 PC100 SDRAM as well.