EggXpert

Hello, I recently purchased RAM that I will unfortunately have to RMA back to newegg, so I could use some help figuring out what WILL work.  I am pretty well versed in most things computer related I would definitely not consider myself a newbie and have built my last 3 computers. 

 A little over a year ago I built my most recent system and at the time had 2GB of RAM.  I decided to upgrade to 4GB so I went to my order history on newegg and clicked thru the original RAM link to buy what I thought would be the same product.  It turned out that what is now offered as the same item that I purchased a little over a year ago has a different EPP profile than the pair that I already had and is causing a system conflict and BSOD's when running memory intensive applications and gaming.  

 The original RAM is http://www.newegg.com/Product/Product.aspx?Item=N82E16820145034

and using  PC Wizard 2008 I generated a report that I will cite from for specs.

 Here is the original RAM:

>> Information SPD EEPROM (A0)
      Manufacturer : Corsair
      Part Number : CM2X1024-6400C4  
      Serial Number : Unspecified
      Type : DDR2-SDRAM PC2-6400 (399 MHz)  -  [DDR2-800]
      Format : Regular UDIMM (133.35 x 3)
      Size : 1024 MB (2 ranks, 4 banks)
      Module Buffered : No
      Module Registered : No
      Module SLi Ready (EPP) : Yes
      Width : 64-bit
      Error Correction Capability : No
      Max. Burst Length : 8
      Refresh : Reduced (.5x)7.8 µs, Self Refresh
      Voltage : SSTL 1.8v
      Prefetch Buffer : 4-bit
      Manufacture : Week 23 of 2006
      Supported Frequencies : 270 MHz, 400 MHz
      CAS Latency (tCL) : 4 clocks @270 MHz, 5 clocks @400 MHz
      RAS to CAS (tRCD) : 4 clocks @270 MHz, 5 clocks @400 MHz
      RAS Precharge (tRP) : 4 clocks @270 MHz, 5 clocks @400 MHz
      Cycle Time (tRAS) : 13 clocks @270 MHz, 18 clocks @400 MHz
      Min TRC : 15 clocks @270 MHz, 22 clocks @400 MHz
     
      EPP Profile #1 : Full Performance
      Voltage Level : 2.1V
      Address Command Rate : 2T
      Cycle Time : 2.5ns @400 MHz
      CAS Latency (tCL) : 4 clocks
      RAS to CAS (tRCD) : 4 clocks
      RAS Precharge (tRP) : 4 clocks
      Cycle Time (tRAS) : 12 clocks
      tRC : 22 clocks
      tWR : 6 clocks

  This is the recently purchased RAM that I bought by clicking through the same link in my order history:

>> Information SPD EEPROM (A2)
      Manufacturer : Corsair
      Part Number : CM2X1024-6400C4  
      Serial Number : Unspecified
      Type : DDR2-SDRAM PC2-6400 (399 MHz)  -  [DDR2-800]
      Format : Regular UDIMM (133.35 x 3)
      Size : 1024 MB (1 ranks, 8 banks)
      Module Buffered : No
      Module Registered : No
      Module SLi Ready (EPP) : Yes
      Width : 64-bit
      Error Correction Capability : No
      Max. Burst Length : 8
      Refresh : Reduced (.5x)7.8 µs, Self Refresh
      Voltage : SSTL 1.8v
      Prefetch Buffer : 4-bit
      Manufacture : 2000
      Supported Frequencies : 270 MHz, 400 MHz
      CAS Latency (tCL) : 4 clocks @270 MHz, 5 clocks @400 MHz
      RAS to CAS (tRCD) : 4 clocks @270 MHz, 5 clocks @400 MHz
      RAS Precharge (tRP) : 4 clocks @270 MHz, 5 clocks @400 MHz
      Cycle Time (tRAS) : 13 clocks @270 MHz, 18 clocks @400 MHz
      Min TRC : 15 clocks @270 MHz, 22 clocks @400 MHz
     
      EPP Profile #1 : Full Performance
      Voltage Level : 2.1V
      Address Command Rate : 2T
      Cycle Time : 2.5ns @400 MHz
      CAS Latency (tCL) : 4 clocks
      RAS to CAS (tRCD) : 4 clocks
      RAS Precharge (tRP) : 4 clocks
      Cycle Time (tRAS) : 12 clocks
      tRC : 102 clocks
      tWR : 26 clocks

As you can see the EPP Profile info is different, as well as the design of the sticks themselves.  

My question, as I was referred here by newegg customer service, is what corsair 2x1GB sticks will be compatible with my original sticks or since I am not pleased with this apparent bait and switch is there a competitor's RAM that will be compatible with my original sticks.  Or should I just go with new 2x2GB sticks and if so can I get a recommendation.

 If anyone needs the full mobo spec report to help I will be happy to post it I just didn't want to clutter this post up too much.

 Thank you.

We've had a few similar posts in the past about this situation. Corsair appears to be one company that will switch chips in a series without telling anyone. There's been reviews stating that they start a series selling their memory with Micron D9 ICs and then switch to the lesser quality ProMOS ICs. Don't really have answer for the Corsair thing. Best thing to do is buy kits at the same time, even though you're still not even guarenteed 100& match. Most other brands though, if you order the same kit, you'll get the same chips, and timings, etc. I think Crucial though is another company you risk getting different makes of a series.  (Though I don't think they have to guarentee compatibility, as a rule. Could be off on that one. But all the same, understand why folks would feel burned by the issue) I'd suggest looking at OCZ, Mushkin, can never go wrong there. (I guess one should never say never, but whenever I've added 2 x 512MB with both, not had any probs.)

Peace, Penewah!