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Dual channel DDR

By bretty · 18 replies
Jun 1, 2003
  1. Dual chanel DDR


    I have a gig of DDR 400 on a single chanell MOBO (SiS648)

    If I buy a new MOBO with support for Dual channel DDR, then will I need to buy more sticks of RAM? Like does the RAM itself need to support Dual channell?
    I have 2 512MB Kingston DIMM'S

    Will the performance increase be huge or a little?
  2. CompuGeek247

    CompuGeek247 TS Rookie Posts: 19

    I think they have to be DDR 400 ram.
  3. bretty

    bretty TS Rookie Topic Starter Posts: 92

    Will buying Dual Channell DDR improve performance heaps? or just a little.

    I cant seem to find a site that has benched Single Channell VS Dual Channell

  4. young&wild

    young&wild TechSpot Chancellor Posts: 993

    Perhaps this might help, here and too.
  5. novicegamer

    novicegamer TS Rookie Posts: 89

    It will improve your performance but not worth the money
  6. bretty

    bretty TS Rookie Topic Starter Posts: 92


    I guess Dual is the way to go. Ill let you know
  7. Nic

    Nic TechSpot Paladin Posts: 1,549

    All you need is two identical sticks of DDR. There is no *special* RAM required for running in dual-channel mode - its all the same.
  8. bretty

    bretty TS Rookie Topic Starter Posts: 92

    I have 2 sticks of the same DDR RAM.

    I have bought the GA-8SQ800 MOBO. There have been some good reviews about this board.

    Thanks again.

    Bretty out.,
  9. young&wild

    young&wild TechSpot Chancellor Posts: 993

    No worries mate...have a nice time doing your system "transplant";)!
  10. bretty

    bretty TS Rookie Topic Starter Posts: 92


    I have recieved the new MOBO, and to my suprise I got a call from the retailer

    Store --> "Ahh Hi, is Bretty there please....."
    Bretty --> Yes this is him.
    Store --> I was just wondering, we have your board in stock now, although there has been a little mistake"
    Bretty --> "Yeah like what"
    Store --> Well we have got the ultra instead, would you MIND if we have that to you for the same price?"
    Bretty --> Cough and splutter, MIND? not at all!! What are the extra features?
    Store --> Well this one has RAID, and Serial ATA and onboard Gigabit Ethernet"
    Bretty --> Thanks that will be grand!"

    Now I have the board, there seems to be a little problem, I have enabled Dual DDR in the BIOS (the latest one) although it keeps reporting "Single 333 in 128 bit mode."

    What can I do about this? I have the latest BIOS, and have the DIMM's configured properly. Anyone have this board?

    Its the GA-8SQ800 'Ultra'

  11. Rick

    Rick TechSpot Staff Posts: 4,572   +65

    Is there no way to manually override the memory clock? You should be able to manually increase your memory speeds to 400 since it isn't doing it for you automatically.
  12. bretty

    bretty TS Rookie Topic Starter Posts: 92


    After a 2nd tinker in the BIOS, I have discovered that the DualChanel DDR option must be DISABLED in order to use DC.

    I have noticed aswell that the speeds interface has changed.
    It used to read

    "DDR333 in 128 bit mode"

    Now it is reading

    "DDR400 running in 64 bit mode"

    Which one would prove to be faster?

  13. Alsep

    Alsep TS Rookie

    Dual Channel problems in Gigabyte mobo

    Can anyone help please?

    My PC configuration is as follows:

    Motherboard: Gigabyte GA-8IG1000
    P4 S478 2,80 GHz HT FSB 800 box (14X200)
    RAM Kingstone DDR 512 Mb PC-400 KVR400X64C3/512 CL3
    Video onboard, AGP slot supports 8X/4X mode
    Sound card onboard: Realtek ALC655 CODEC
    Windows 98 SE

    My PC is working on a single memory stick Kingstone DIMM 512 Mb PC-400 KVR400X64C3/512 CL3. I have read in the manual the mobo supports Dual Channel DDR technology. The conditions mentioned there include:

    1. For P4 FSB 800 MHz it should be DIMM 400MHz
    2. The memory stick should be the same size and type and should be inserted in different channels.
    (The channels are usually marked with the same color so it’s difficult to make mistake.)

    BIOS recognizes 2X512 Mb RAM, after booting Windows seems to load correctly. The message says: 1024000 byte memory working in dual channel. Everything seems fine until the last moment when it should switch to 1024X768 32 bit video but it does not.
    There’s only small rectangle with navy vertical lines in left upper corner of the screen. I found the only working configuration is 640x480 pixels with 16 colors. This is actually Windows safe mode. But even then the memory doesn’t seem to work well. For example Norton Internet Security says: Can’t load virus definitions …etc.
    I also tried both sticks of memory working in a Single Channel putting them into the same bank. Windows doesn’t load at all. However, BIOS sees the amount of RAM right.

    Each stick of memory works fine separately as 512 Mb RAM.

    Any suggestions? Please help.
  14. fishhookz

    fishhookz TS Rookie Posts: 79

    Run memtest86 _ com for 30 mins. If it reports 0 error, the RAM and RAM settings are ok.

    BTW, did you do a fresh install of Windows after mobo upgrade? Or at least, uninstalled old mobo drivers?
  15. nein

    nein Banned Posts: 109

    Win9x series do not like 1GB of real memory.
  16. Alsep

    Alsep TS Rookie

    Dual Channel Windows 98 SE problems

    Here are some conclusions I came to after experimenting with Windows 98SE and dual channel RAM.

    PC configuration:
    Motherboard: Gigabyte GA-8IG1000
    P4 S478 2,80 GHz HT FSB 800 box (14X200)
    RAM Kingston DDR 512 Mb PC-400 KVR400X64C3/512 CL3
    Video onboard, AGP slot supports 8X/4X mode
    Sound card onboard: Realtek ALC655 CODEC
    Windows 98 SE

    I bought a new stick of Kingston KVR400X64C3/512 CL3 and inserted it into another bank of memory. Both banks A and B have the same memory size, type and make, but they were bought separately and were not matched for dual channel.
    I have run Memtest86 both standard and extended tests for more than one hour each and no errors reported. I have also run Windows Memory test standard and extended tests and no errors either.

    Conclusion: My mobo Gigabyte GA-8IG1000 with two Kingston KVR400X64C3/512 CL3 supports dual mode although they were neither matched nor sold as dual channel.

    However, Windows 98 SE still doesn’t work properly on 1 Gb dual channel RAM.
    Apparently the problem is with memory management or memory mapping. I read in Microsoft database that too much RAM can cause problem in Windows 9X and Me.
    The limitations are as follows:

    Windows 95 128 Mb RAM
    Windows 98 256 Mb RAM
    Windows 98 Second Edition 512 Mb RAM
    Windows Me 1 Gb RAM

    My Windows 98 SE runs flawlessly on 1 stick of 512 Mb Kingston, but it can’t handle 1024 Mb RAM in dual channel mode. I tried to limit the memory size accessed by Windows adding MaxPhysPage=20000 (which is equivalent to 512 Mb RAM) but still it didn’t help.
    I’m tired of these experiments so I don’t feel like experimenting with 512 Mb limitation on 1 Gb single channel mode. I bet it will work but it’s no point putting more RAM in single channel and making such a constraint.

    I doubt if Windows 9X/ME can handle dual channel memory.
    If you want to upgrade your RAM working in single channel by adding one more stick of RAM into another channel you will definitely have problems unless you switch to Windows XP, Windows 2000 or Linux.
    A fresh installation of Windows 98 SE might help. I will have to find out it later.
  17. Blakhart

    Blakhart TS Rookie Posts: 353

    Along with the others, I say you need to get a better os first. 98 will do up to 256 without probs, after that you're asking for it. Don't worry abt benchmarks, xp or 2k will be as fast or faster than 98/me.

    As to dual channel mem, the mem speed is irrelevant, as is the need for any kind of "dual channel mem". They're (they being ram) all 64bits wide, the channel depends upon the controller for the dual ability. By the way, 64bit means the mem controller is running single channel, 128bit means it's running dual. I'd take dual at 333 over single at 400.

    The diff in mem controller performance between say a nf2 and a Intel 865 chipset can be kinda funny. My last nforce2 mobo got like 1394 in memtest86 as the mem bw score. Same mem in a 3GHz p4 sys got 2570. That just shows the different implementations. The nforce2 dual channel isn't really dual channel, it's meant to better support the onboard grafix and sound than overall performance.
    The Intels and the new (say like nforce3 and higher) nforce systems, along with the via 880 seem to all use dual channel mem in the "right" way.
    Letting all devices have access to the creamy goodness that is 128bit mem access, not just onboard devices.

    Some thoughts for you.
  18. Brendonmc

    Brendonmc TS Rookie

    different RAM makes

    Hi there

    I have curreny 1x512MB ram in my PC, with the motherboard supporting Dual Channel DDR - Im not sure if I will be able to get the same make of ram if I add another 512MB ram. Would this cause a problem?


  19. Tedster

    Tedster Techspot old timer..... Posts: 6,000   +15

    why wouldn't you be able to get the same type of ram?

    For DDR to work best, make sure you have same brand and type and run it in pairs.

    i.e. 2 x 512mb
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