TechSpot

Help Needed: RAM OCing - Confused and CPU OCing - Problem

By thehacker
Jan 15, 2008
  1. Hi all,
    RAM PROBLEM: I want to SLIGHTLY overclock my RAM. Its 512MB, DDR2 533Mhz.
    But I am confused, how to do it.
    Let me tell you the options available for RAM is my mobo's bios:

    1. DRAM Timing:
    a. Auto
    b. Turbo
    c. Ultra
    d. Manual
    DRAM CAS# Latency [DDR/DDR2] 2.5/4(current setting)
    DRAM Bank Interleave 4-Way
    Precharge to active (Trp) 4T
    Active to Precharge (Tras) 7T
    Active to CMD (Trd or Trcd) 4T
    REF to ACT/REF to REF(Trfc) 25T
    ACT(0) to ACT(1) (Trrd) 3T
    Read to Precharge (Trtp) 2T
    Write to Read CMD(Twtr) 1T/2T
    Write Recovery Time (Twr) 4T

    2. DRAM Driving: Normal
    High

    3. CPU PnP Setting > DRAM Frequency:
    200
    266
    333
    400
    533
    666
    Auto(current)

    Now, which of these settng I need to change to overclock my RAM?? And by how much???


    Problem With CPU:
    My Processor is Pentium D 2.8Ghz.
    200(Bus Speed) x 14(multiplier) = 2800mhz
    Now, when I slowly increase the BUS speed from 200 to 223, everything is fine. Under stress too, there is no problem. But as soon as I change the FSB to 224 or higher, my whole harddisk becomes corrupt. I need to reinstall Windows again after this. One time, even WinXP setup was not running by booting with setup CD. That time I installed win2k(it ran) and then installed XP. After that incidence, I have never OCed my CPU over 223 Bus speed.
    Now, can u guess what may be causing this problem??

    Thanks in advance
    Regards,
    TheHacker
     
  2. Cinders

    Cinders TechSpot Chancellor Posts: 1,313   +12

    To slightly overclock your ram you'll need to set the dram timings to auto for now. As you speed up your FSB, your BIOS should automatically increase the memory timings to ensure stability. Set the dram frequency to 533 and then slowly increase the front side bus. After you have the FSB set you can then set the dram timings to manual and tighten your memory timings one at a time and then test for stability.

    As far as your hard drive is concerned, it sounds like when you increased the FSB frequency your South Bridge frequency also increased. South Bridge devices (like your hard drive controller card) don't usually respond well to an increase in speed, so the card scrambled your hard drive. There should be a South Bridge lock in your BIOS. Your South Bridge should remain at 100MHz if it's a PCI-E based SB or 33MHz if it's a PCI based SB.

    Now I may be completely wrong about your hard drive problem. Your processor could have over heated and caused the same thing; your memory could have spazzed and caused the same thing.

    Honestly there are far to many variables to be able to help you at your current level of knowledge, and I don't know much if anything about overclocking DDR2. You need to read as much as you can about overclocking. Then start slowly and overclock you processor. Pull back and overclock your memory. Find out what will be your limiting factor (either your processor, memory or motherboard) and set up your BIOS to run as fast as possible with stability.
     
  3. thehacker

    thehacker TS Enthusiast Topic Starter Posts: 176

    Thanks a lot Cinders for your great help.

    2 things I would like to ask:
    You wrote:
    Well, I have a confusion here. When we calculate FSB : DRAM Frequency ratio, we put DRAM frequency as 266 for DDR2 533Mhz. That is the actual frequency at which the RAM works.
    So, I need to set the DRAM Frequency in BIOS as 266 or 533(as you have said)??



    And another question is:
    If CPU becomes unstable, we can undo the changes by BIOS, atleast we can access BIOS and system boots upto that.
    But what if Memory becomes unstable?? Will I be able to access BIOS and undo the changes under any mishappening? Or will I have to clear my CMOS memory everytime there is a problem, by removing the CMOS battery???
     
  4. thehacker

    thehacker TS Enthusiast Topic Starter Posts: 176

    And Can u please give link of any GOOD FREE site, which can teach me basics of computer hardware and their working??? I know only howstuffworks.com. :(

    You know, where I live, people are so much ignorant of this computer world that, I am intelligent among them. No computer hardware shopkeeper knows more than me here. :(:(.......but :D :D too........
    So, I need to get more knowledge...atleast what every computer user should know.
     
  5. Cinders

    Cinders TechSpot Chancellor Posts: 1,313   +12

    I probably made a mistake when I told you to set the dram frequency to 533. Please set the dram frequency to 266.

    This site is dedicated to overclocking. You'll be able to learn quite a bit there.
    http://forums.extremeoverclocking.com/
     
  6. thehacker

    thehacker TS Enthusiast Topic Starter Posts: 176

    Now, I have got a DDR2 2GB RAM 667Mhz. When I started my system under DRAM Frequency = Auto, CPU-Z showed frequency 266.7Mhz. But when I start my system under DRAM Freq. = 666, CPU-Z is showing nothing in Memory Frequency. I have only this 667Mhz DDR2 RAM in the slot, 2nd slot is empty.
    What is the problem? And at what speed my RAM is running? 533Mhz or 666Mhz?



    To Cinders:
    You didnt made a mistake, I tried 333Mhz and CPU-Z showed DRAM frequency 166 Mhz. When I changed it to 533, CPU-Z showed 266 and when changed it to 666, CPU-Z showing no frequecy. It seems that in BIOS we have to enter the effective frequency.
     
  7. Cinders

    Cinders TechSpot Chancellor Posts: 1,313   +12

    Your motherboard doesn't support an FSB of 667, and it probably doesn't support a 2GB memory dimm in a single slot. Your motherboard can handle 2GB total and that usually means 1GB memory dimm per slot. A close look at the chipset manufacturer's website (VIA) didn't mention anything about dual channel memory support so your motherboard probably doesn't support that either. To get the most from your motherboard you'll need to purchase 2 1GB DDR533 memory dimms.

    http://www.mercury-pc.com/product-spec.php?productid=677
    http://www.via.com.tw/en/products/chipsets/p4-series/p4m800_pro/
     
  8. thehacker

    thehacker TS Enthusiast Topic Starter Posts: 176

    I have purchased 1GB right now. DDR2 667 Mhz. I have set the DRAM Freq. in BIOS as Auto, and in CPU-z, memory freq. shown is 266.7Mhz.
    But once I changed itto 666Mhz and comp started with no problems, but CPU-z showed nothing in Memory's Freq.
    I am asking, that after selecting 666Mhz in BIOS, and as my RAM is 667Mhz, was my RAM working at 666Mhz or 533Mhz, I was unable to find this as CPU-z showed nothing...... :(
     
  9. Cinders

    Cinders TechSpot Chancellor Posts: 1,313   +12

    The only thing I can think to do is download/install Sandra Lite. Run the memory bandwidth benchmark ten times and average the results. Then reboot your computer and set your memory to 666. Run the Sandra memory bandwidth benchmark ten more times and again average the results. If you get significantly better results with the memory set at 666 then your board may support the faster memory speed. If you don't get better results then your board probably doesn't support the faster memory speed.

    Just because the higher memory speed is in your BIOS doesn't mean that it works. :(
     
Topic Status:
Not open for further replies.


Add New Comment

TechSpot Members
Login or sign up for free,
it takes about 30 seconds.
You may also...


Get complete access to the TechSpot community. Join thousands of technology enthusiasts that contribute and share knowledge in our forum. Get a private inbox, upload your own photo gallery and more.