jgv115 Posted May 25, 2009 Posted May 25, 2009 I have a Pentium 4 520 (Prescott). It's base clock is Multiplier: 14 Bus Speed: 200 = 2.8ghz Right now I got it at Multiplier: 14 Bus Speed: 249 =3.49ghz (running on the lowest possible vcore, already tested for stability) When I try to go to 250 bus speed, my computer won't let me. I don't know why this is but it just won't let me. The temperatures are fine. 50 degrees celcius under load. I also saw the "Rated FSB" on CPUZ and that says 997mhz, has this got anything to do with not being able to reach 251 bus speed? I have DDR RAM. I will post more info if needed Any help is appreciated Share this post Link to post Share on other sites More sharing options...
jgv115 Posted May 25, 2009 Posted May 25, 2009 Also, can anyone help me set these options in the BIOS: Share this post Link to post Share on other sites More sharing options...
SAJBAMA Posted May 25, 2009 Posted May 25, 2009 How do you mean it wont let you?Reboots?By increasing the FSB you increased also the Ram clock.That means the Ram requires more voltage to run at higher clocks with the same timings and may cause the failure.You need to loosen the timings which means you increase the numbers say 3-4-4-15 to 4-5-5-18 or even 5-5-5-18 or more if needed,than you will see if the problem is in the timings or not,after you loosen them be sure to trim them again to a stable but faster value.You could also decrease the clock of rams by choosing a different fsb/ram ratio,be sure to check what you have now.You could try 1:1,1:2,3:5 eg.Whats the rated speed of the ram,volts and timings?Because if you have eg. DDR 400MHZ RAM with the default 200FSB it is 400MHZ with the 1:2 Ratio but when you increase the FSB to 249MHZ it is 498mhz (assuming you havent changed the default ratio) on the ram which means its probably needs more volts to run on 250 or loosen the timings or choose a different Ratio to lower the ram speed because 498 could be ok,500 just could be too much.Also check for fsb walls try a higher FSB with lower Multi and be sure to lower the ratio with the higher fsb.I did clocked my 400DDRs to 500MHZ with a bit of more voltage and a bit loosen timings try that Share this post Link to post Share on other sites More sharing options...
jgv115 Posted May 26, 2009 Posted May 26, 2009 Alright.. thanks for your reply can you explain to be what those timing settings mean? Share this post Link to post Share on other sites More sharing options...
jgv115 Posted May 26, 2009 Posted May 26, 2009 I've changed the timings to 2.5-3-3-13 then tried to up the FSB and it won't work I think the only left option is to change the memory divider. The problem is I don't know where to find the option to change the memory divider. Does anyone know what else it can be called (besides memory divider) Share this post Link to post Share on other sites More sharing options...
maj0rgamer Posted May 26, 2009 Posted May 26, 2009 (edited) rather than mess with the timings, you should perhaps increase the voltage for the memory... only in very, very small (example: from 1.8v to 1.9v) increments! also, the cpu probably needs more voltage to run at that speed... try increasing the cpu voltage (v-core) very slightly (again, very small increments... as small as possible to be safe). if you continue to tweak the voltage it should lead to a stable system. make sure to test for stability with prime 95 or occt if you're not doing that. Edited May 26, 2009 by Maj0r Gamer Share this post Link to post Share on other sites More sharing options...
jgv115 Posted May 27, 2009 Posted May 27, 2009 I'm starting to become a little frustrated. I tried raising the ram voltage from 1.6V to 1.8V, that didn't work (i turned it back to 1.6V because i thought my RAM would fry) I have raised the Vcore to 1.5V (default is 1.37V) that's a massive jump. Still not working. What else can I try? I am disapointed because the CPU ran so perfectly at 249 bus speed with cool temperatures with stock fan+heatsink. I think I could easily take this CPU to 4GHZ Anyone got any other suggestions? Share this post Link to post Share on other sites More sharing options...
slick2500 Posted May 27, 2009 Posted May 27, 2009 What motherboard are you using? I am going to assume from the screenshot its an Asus, but it would be much more help full if you gave us the model. What ram are you using? Brand, model stock speed and timings. Try again to loosen the timings not tighten them. Make the numbers bigger not smaller. The more info that you give us the better. Share this post Link to post Share on other sites More sharing options...
jgv115 Posted May 27, 2009 Posted May 27, 2009 I'm using an old mobo (obviously) P5GD1 PRO is the model and it is ASUS I'll try to loosen timings so they cannot be loosened anymore. I'm using DDR PC2700 RAM Share this post Link to post Share on other sites More sharing options...
slick2500 Posted May 27, 2009 Posted May 27, 2009 I might be wrong but your ram may be what is limiting your overclock. Share this post Link to post Share on other sites More sharing options...
jgv115 Posted May 27, 2009 Posted May 27, 2009 Understandable. Do you know how the RAM could be limiting my overclock? Is there a reason behind it? Share this post Link to post Share on other sites More sharing options...
maj0rgamer Posted May 27, 2009 Posted May 27, 2009 (edited) are you using a stock cpu cooler? what temp monitoring program are you using? may wanna check temps with another program to make sure the readings are reliable. what are all of the system specs, including power supply? what brand of ram is being used? "turned it back to 1.6V because... thought... RAM would fry"... perhaps this is the problem, maybe a cooling solution for the ram would help {does the ram atleast have heatsink(s)?} Edited May 27, 2009 by Maj0r Gamer Share this post Link to post Share on other sites More sharing options...
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