Craterspace Posted January 21, 2012 Share Posted January 21, 2012 I have an old Althlon64 system that I am trying to keep running. It has a Foxconn K8S755A motherboard with 3 DIMM slots. Two of these contain Corsair VS512MB400 and I just bought a third of the same spec to go in slot 3. Unfortunately the system crashes (about once an hour) with the third stick in place. The BIOS is set to auto detect settings and Speccy tells me the following has been set: Type DDR Size 1024 MBytes Channels # Single DRAM Frequency 199.9 MHz CAS# Latency (CL) 2.5 clocks RAS# to CAS# Delay (tRCD) 3 clocks RAS# Precharge (tRP) 3 clocks Cycle Time (tRAS) 8 clocks Bank Cycle Time (tRС) 11 clocks Command Rate (CR) 2T I have run memory tests with all three sticks in place and they show no faults. I wonder if the additional load of the third stick is just bringing the system into the unstable area. I am wondering if increasing the latencies may help (e.g. CAS# from 2.5 to 3). Can anyone advise me on this or any other ways of improving the stability without slowing it down too much. Thanks for any help. Link to comment Share on other sites More sharing options...
Synthohol Posted January 22, 2012 Share Posted January 22, 2012 it may never work im afraid, mixing kits is not supported. read the 2 links below. a 2 gig matched set would have been a better choice. Link to comment Share on other sites More sharing options...
Craterspace Posted January 22, 2012 Author Share Posted January 22, 2012 Thanks for your reply and the helpful links. The Motherboard claims to support three "single rank" memories at 200MHz max. or three "double rank" memories at 166MHz max.. Would you know how many "ranks" the VS512MB400 has? Thanks for any help. Link to comment Share on other sites More sharing options...
Craterspace Posted January 23, 2012 Author Share Posted January 23, 2012 Since my last post I have noticed that the new VS512MB400 contains different information in its SPD Memory to the published specification and indeed the two older DIMMs (not bought as a kit). New VS512MB400 Frequency 200.0 MHz CAS# Latency 3 RAS# To CAS# 3 RAS# Precharge 3 tRAS 8 Voltage 2.500 V JEDEC #1 Frequency 166.7 MHz CAS# Latency 2.5 RAS# To CAS# 3 RAS# Precharge 3 tRAS 7 Voltage 2.500 V Originals JEDEC #2 Frequency 200.0 MHz CAS# Latency 2.5 RAS# To CAS# 3 RAS# Precharge 3 tRAS 8 Voltage 2.500 V JEDEC #1 Frequency 133.3 MHz CAS# Latency 2 RAS# To CAS# 2 RAS# Precharge 2 tRAS 6 Voltage 2.500 V The new part has a CAS Latency of 3 whereas the spec quotes 2.5-3-3-8. Does this mean the more recent parts are slower or not compatible in some way? There is no information on the product wrapping or the vendors website to indicate that these parts are not suitable for upgrading. Link to comment Share on other sites More sharing options...
Corsair Employee RAM GUY Posted January 23, 2012 Corsair Employee Share Posted January 23, 2012 The part that shows VS512MB400 Cas 2.5 will be double rank and the part that shows VS512MB400 Cas 3 will be Single rank in most cases but they can be made either way on either part. We do not have a way to specify single rank on this part sorry! Link to comment Share on other sites More sharing options...
Craterspace Posted January 24, 2012 Author Share Posted January 24, 2012 If I ditch all these and get a VS2GBKIT400C3 2 stick kit can I be sure that they will run at the full speed (200MHz clock)? Link to comment Share on other sites More sharing options...
Corsair Employee RAM GUY Posted January 27, 2012 Corsair Employee Share Posted January 27, 2012 It will depend on the MB and CPU, but in most cases if its a socket 939 it should be no problem. Link to comment Share on other sites More sharing options...
Motolito Posted March 29, 2012 Share Posted March 29, 2012 The part that shows VS512MB400 Cas 2.5 will be double rank and the part that shows VS512MB400 Cas 3 will be Single rank in most cases but they can be made either way on either part. We do not have a way to specify single rank on this part sorry! Hi RAM GUY, recently I bought a 512 MB DDR Value Select memory module (VS512MB400). http://www.corsair.com/memory-by-product-family/value-select-memory-upgrades/vs512mb400.html In theory, the CAS latency is 2.5-3-3-8 . But when I use test software like CPU-Z, AIDA64 and SiSoftware Sandra CAS latency is 3-3-3-8 . Also in these programs the part number(model) of memory is VS512MB400C3. The IC chips are 64M8BDCG. What is wrong with my memory module? Why not supports CAS latency 2.5 ? On the sticker it appears this information: 120300991 VS512MB400/EU G QTY: 1 MADE IN TAIWAN 8 70584 00130 0 Moreover, years ago I bought another 512 MB DDR Value Select memory module (VS512MB400). This older memory module supports CAS latency 2.5 The IC chips are 64M8BDAG . On the sticker of this older memory module it appears the following information: 090750500 VS512MB400/EU G ASSY IN TAIWAN 8 70584 00130 0 Both memory modules, are 1 rank. Best regards. Link to comment Share on other sites More sharing options...
Corsair Employee RAM GUY Posted March 31, 2012 Corsair Employee Share Posted March 31, 2012 All of the DDR400 parts VSXXXMB400 will be Cas 3 there are no Case 2.5 IC's available any more. Link to comment Share on other sites More sharing options...
Motolito Posted March 31, 2012 Share Posted March 31, 2012 All of the DDR1400 parts VSXXXMB400 will be Cas 3 there are no Case 2.5 IC's available any more. Hi RAM GUY, thank you very much for the information. Corsair is providing wrong specifications with VS512MB400 http://www.corsair.com/memory-by-product-family/value-select-memory-upgrades/vs512mb400.html because in tech specs section appears Tested Latency 2.5-3-3-8 SPD Latency 2.5-3-3-8 but the real latency is 3-3-3-8 :wtfeh: Corsair should modify the specifications to not confuse customers. Link to comment Share on other sites More sharing options...
Corsair Employee RAM GUY Posted April 3, 2012 Corsair Employee Share Posted April 3, 2012 That is an old spec and no longer in production. But yes you are correct I will ask for our web master to update the spec sorry about that. Link to comment Share on other sites More sharing options...
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