5 Replies Latest reply on Mar 7, 2011 7:47 PM by Seven ltd

    Advice on buying memmory


      I wanted to know how much of a performance difference is there between ddr3 1333 and ddr3 1600 and different cas latency of 9 or 7. I will be getting 4 4gb stcicks of memmory for my p67 system.

        • 1. Re: Advice on buying memmory
          Harm Millaard Level 7

          If you run the memory at its rated speed, 1600 with CL9 will be faster than 1333 with CL7. However the performance gain will be relatively small, think a couple of %.

          • 2. Re: Advice on buying memmory
            ECBowen Most Valuable Participant

            In memory bandwidth testing on the Sandy, 1333 gives around 17GB/s a sec and 1600 gives around 19GB/s a sec.




            1 person found this helpful
            • 3. Re: Advice on buying memmory
              Seven ltd Level 1

              I am just ready to order the parts to my new PC when I started to get worried about memory.


              I plan to order MB ASUS Rampage III Formula and CPU i7-950.


              To that I also planned to order RAM G.SKILL DDR3 12GB RL 1600(4GBx3) x 2 (together 24 GB).


              I live in Thailand and cannot order from US, have to find all the parts in Bangkok. So here is the info about this RAM:


              Main Boardintel
              System TypeDDR3
              M/B ChipsetIntel X58
              CAS Latency9-9-9-24-2N

              12GB (4GBx3) /

              24GB (4GBx6)

              SpeedDDR3-1600 (PC3 12800)
              Test Voltage1.5 Volts
              Error CheckingNon-ECC
              Type240-pin DIMM


              Qualified Motherboards List


              ASUSRampage II Extreme
              ASUSRampage II GENE
              ASUS P6X58D Premium
              ASUSP6TD Deluxe
              ASUSP6T Deluxe V2
              ASUSP6T Deluxe
              EVGAX58-CLASSIFIED 4-WAY SLI
              MSIX58 Pro-E
              MSIX58 Pro

              I try to check that it is OK on Gskill website, they have a RAM Configurator, but the info is not up to date. The new generation of ASUS motherboards are not there.


              And as you see in the above information my planned MB is not in the Qualified list. But I think/hope that the info is not updated and the RAM will work with the Rampage III Formula.


              So can someone please tell me if if I can use the G-skill!


              (the reason I prefer them is that the price is very good, almost half compared to Kingston and we do not have so many to choose among)


              Thanks in advance !







              • 4. Re: Advice on buying memmory
                wb_martin Level 1

                I have the Rampage III Formula motherboard and populated it with 24 GB of GSkill, F3-12800CL9D-8GBRL, DDR3-1600-PC3-12800, (which is 4GBx6) using vendor-specified settings.  A couple of notes:


                • I had to RMA a couple of sticks because they failed memtest86+ testing at the labelled speed.  They worked fine at 1033, but not at 1600.  You should test each stick SEPARATELY in slot A1 with no other memory installed.  I suggest testing all sticks keeping track of serial numbers while doing it. When you're done, I also suggest running memtest86+ on the system with all sticks (24 GB) installed - but be prepared to wait a while for it to finish!   Of course, all of this means that you need to boot the computer to a bootable CD with memtest86+ on it several times - and with each reboot reset BIOS with each removal/insertion of a new stick - which is a royal pain in the butt.


                • I run the memory now at about 1.4975V, but aI am not overclocking it yet (while I learn more about exactly how to overclock).  I am told that at some point it may be necessary to "bump" the memory voltage up a little to ensure a more stable overclocking.  That was one feature of the GSkill memory that I liked - a 1.5V memory requirement - less stress/strain on related voltages from my ignorant perspective.


                • After I checked the Vendor Recommended List for memory for the Formula board and actually bought the memory, for some reason ASUS removed all 24GB total memory options for the Formula board from their current online list.  (When compared to the printed manual, the lists are different too).  I tried to find out why but never got a satisfactory response.  I spoke to the folks at GSkill (great online forum - suggest you sign-up athttp://gskill.us/forum/forumdisplay.php?f=2 ) and they assured me all would be OK and walked me through settings, installation, and testing. ASUS also has an online forum which you can post on, located at http://vip.asus.com/forum/topic.aspx?board_id=1&model=Rampage+III+Formula&SLanguage=en-us



                You do not mention your plans for disks in your system but you should be aware that the Marvell drivers for the SATA III ports on the ASUS motherboards (Formula included) DO NOT support TRIM functions for SSDs installed on those ports and from what I have learned, drop back to SATA II settings with slower performance than just plugging the SATA III device into the mobo SATA II port using MSACHI drivers.  The message here is, be aware/learn more.


                Good luck!

                • 5. Re: Advice on buying memmory
                  Seven ltd Level 1

                  Thank you Martin !


                  But I do not know what to say. This is my first PC that I will try to build myself and with my level of experience I wonder if I even shall try to start doing that after I read your very informative post.

                  My only experience building goes back to beginning of the 90's when I added memory, changed the harddrive, added communication etc on PC's. At that time the PC's were not that sensitive and probably more robust.


                  So maybe I should try to find another RAM that is more foolproof to install and without the hazzle (if there is one ).


                  Because what I understand from what you are saying, I must boot the PC for each memory with resetted BIOS and run the memtest and if they fail I have to RMA ? Is that that I have to change something in the BIOS for this particular memory stick and then boot again, do the memorytest to see it is working?


                  And then in the end I might have different settings in the BIOS for each memory stick or is it that I have to use the lowest value for all of them (probably).


                  When it comes to disks I am planning to use one WD Caviar Black Desktop Hard Drives 500 GB for OS and 3 or 4 Samsung Spinpoint F3 1 TB 7200RPM 32 MB Cache.


                  So if you Martin or someone else have another RAM that might be foolprof I think I will try to find that and go for that. One alternative might be to order just the RAM from US (I live 65 km south of Golden Triangle, Thailand, in the middle of nowhere...).


                  Thanks again!