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setting memory timings

By K@in
Sep 30, 2006
  1. i have been overclocking my system for the past month or so, but that only leads to heat and instability. i want to try something new - i have read that lowering you ram timings increases bandwidth, so o ned some help on what to set to what value. my system spec are

    athlon 64 3500+ venice core w/ zalman copper cooler
    Asus A8V mobo
    2 gigs mushkin redline memory with the 3-3-2-8 timings @2.6v

    in the bios i have a menu that looks like this:

    MCT Timing Mode
    CAS
    TRAS
    TRD
    TRCD
    TRRD
    TRC
    TRFC
    TRWT
    -------------------
    TWCL
    TWR

    by default, they all are set to auto. could some one please help me with this, for i have no clue on how to proceed.
     
  2. Tmagic650

    Tmagic650 TS Ambassador Posts: 17,244   +234

    Do not overclock in the first place, you won't gain much in overall performance even if you get the system stable again. Your system is trying to tell you something by being unstable in the first place
     
  3. korrupt

    korrupt TS Rookie Posts: 716

    The words of a wise man;)
     
  4. KingCody

    KingCody TS Evangelist Posts: 992   +8

    what was your highest stable overclock? and what settings did you use to get there (FSB, CPU multi, HTT multi, RAM ratio/divider, CPU voltage, RAM voltage)?

    where did you read that? lower timings increases performance, but it does not increase bandwidth. bandwidth is directly related to BUS speed. when you increase the BUS speed (FSB), you also increase the bandwidth.

    even though timings do no directly affect the bandwidth, they can have an impact on it. this is because timings can limit the maximum BUS speed. RAM sticks can operate at higher BUS speeds when set to looser/slower timings, and obviously can operate at tighter/faster timings when set to slower BUS speeds.

    AMD64 systems use a hypertransport BUS instead of a FSB, so they don't need the extra bandwidth and will yield better performance with tighter timings vs. increased BUS speed alone. (on Intel systems, more bandwidth is preferred over tighter timings when tweaking)

    ok, your RAM is rated to operate at 3-3-2-8 @2.6v. those values are CAS-tRCD-tRP-tRAS. so set those 4 values to their rated values. those are what mushkin guarantees your RAM can operate at (within it's rated BUS speed)

    you may be able to set them lower. the best timings you could possibly achieve would be 2-2-2-5/1T. you may be able to get tighter timings by lowering the BUS speed (setting a RAM divider to bring it down to DDR400), or by increasing the RAM voltage (be careful, too much voltage can fry your RAM)

    memory timings and how the effect overall performance can be confusing. I hope this helped a little. let me know if you still need with your timings or the rest of your overclock, I'll be glad to help :)
     
  5. YellowC4S

    YellowC4S TS Rookie Posts: 107

    What kind of motherboard are you using? I would try bumping that ram voltage up to about 2.7v. That redline can take some voltage. I know because I use the same ram. In overclocking, I would do the CPU/FSB first and do the ram last. There are several programs to help do this such as memtest.
     
  6. Tedster

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

  7. K@in

    K@in TS Rookie Topic Starter Posts: 36

    set the timings to 2-3-2-5/2T (1t is completely unstable)@2.8v with 220fsb(220x11@1.425v is the best oc for my system- any thing below doesn't make a difference, anything above doesn't justify for the instability) My system survived 2hrs of prime95, using ~1.7gigs of my memory, but as soon as i launched aquamark or cod2, windows bsods.
     
  8. YellowC4S

    YellowC4S TS Rookie Posts: 107

    Asus A8N-SLI Premium
    AMD64 X2 4400
    Mushkin Redline 2x1024mb
    FSB=265x10 @1.475 vcore @ 2650MHz
    Ram=3-5-3-3-1T, 2.8v @ 530MHz
    Prime 95@22 hours = 55 Celsius

    See my other post here:
    http://www.techspot.com/vb/topic43427.html
     
  9. K@in

    K@in TS Rookie Topic Starter Posts: 36

    i can't really oc past 2.53, because at those speeds, 10 mins in call of duty 2 causes my system hang up(display freezes, sound loops). I have 2 theories why:

    a) might this be because of my 6800u (engeneering sample)? if im using 1.5v on the cpu, might it be pulling all the electicity away from the gpu, causing it to hang up? My brother (from whom i got the card later) oc'd it 450/1250 with his asus nforce 2 ultra 400 and xp 3200+ at 2.5(dunno what voltage) on a suncheer(i think it is made by lite on) 400w psu? wtf? the card now can barely hold 430/1230 now(it artifacts in some games @ those frequencies). the temps are normal under load 62c max, so i think tht it is a voltage problem.

    b) cpu z showed my htt frequency at... ummm.... i think it was 1100 or so. can that be it?

    p.s. are there any other good memory tests except memtest? i have gone through 3 floppy drives with this mobo, and none of the floppy drives seem to work... i dunno why.
    Edit:
    yesssss i lowered the htt to 800 mhz set my vcore to 1.475, fsb to 230x11, and vdimm to 2.7v. memtimings are 3-3-3-8/2T. rock solid stable, cpu never reaches more that 46c. 73k in aquamark, 14k in 3dmark03. Yay!
     
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