Prime95 Error Explaination? i7 860 w/ p7p55 lx

[Four20]

So I have an i7 860 processor, with an ASUS P7P55 LX mobo, 4 chips of DDR3 Corsair 1600Mhz RAM, and stock fan(a better one is in the mail, along with 3 fans to attach to my case so that I can increase airflow).

I used overclock guides listed in this forum(thanks again for that!) along with about 6 other threads on 6 other websites since most people don't overclock with my mobo and processor(I didn't realize I was going to overclock it. . .I mean it is eight 2.8ghz processors lol, so I didn't really research for a good mobo to OC).

So most of the guides say to run Prime95 or other stress testing software on each reboot to find out what is 'stable'. What does the term 'stable' really mean?

I understand that I need to run it for 12+ hours, but does it need to run that long without rebooting(like from overheating), or does it need to run for 12+ hours with ZERO errors?

When I run Prime95 I have 8 'workers', on settings that give me 180 BLCK/FSB on each processor at a total of 3.420Ghz(multiplier of 19). All other settings(besides RAM) stays on auto.

I've had Prime95 stress test using the top option(processor) and 'worker' 4 and 5 give errors immediately and then after 5 minutes 'worker' 2 gives an error(which makes those 3 workers stop testing).

Before that 3rd one errors, the CPU temp gets up to 74C, and when that one drops it goes down to 71C, and then Prime95 runs without anymore errors for however long I run it.

I have a 430W PSU(that came with the antec case), which is going to be replaced this week with a 650W corsair PSU.

Are these errors important since my computer doesn't reboot? Or do any errors at all constitute a reason to lower the voltage, raise the multiplier, etc?


Quick specks on my OC. . .

1.26 Vcore
19 CPU Multplier
180 BCLK




Another quick question about FBS vs Clock Speed. Everyone seems to want to use the highest multiplier possible. Which is a great way to increase the clock speed, but lowers your FBS correct?

My goal is to at LEAST get 3.5Ghz stable with the highest possible FBS. But what I will continue to work on and go for is something like 4.0Ghz with as much FSB as possible(I hope over 200).




And one more quick question about RAM.

I was going 3.5Ghz stable, but had a very low RAM frequency/ratio. I was able to give it a little more Vcore power and lower the clock speed to 3.420 but get my RAM at 1440Mhz at 1.65 volts(with 9,9,9,27 timing).

Spec it should run at 1600Mhz at 1.65 volts with 9,9,9,24 timing. But my board can handle upto 2200.

So if my math is correct, to get my RAM at 2200, I'd have to get my FBS/BCLK to 275? Do you think that will be possible with 4 case fans, and this heatsink( http://www.newegg.com/Product/Prod [...] 6835186134 )? If not what would my best shot be? 250=2000 200=1600 and 225=1800(first # being FSB second # being RAM Mhz).





I always thought overclocking just increased clock speed(cause I never looked into it, seemed too risky to me), and I've always favored FBS to clock speed. But I have literally been up for 60 of the last 96 hours reading forum to forum and doing tests of my own. So I've learned a LOT. I can do a basic OC, which is what I have now, but I'd really like to learn how to get the most of my hardware(with air cooling).

TIA to anyone who can help. I've held myself back from posting questions until I was familiar with what I was doing(and could actually understand the advice I'm given).

 

[RJARRRPCGP]

-> Must be zero errors and zero reboots!

 

[c627627]

Welcome to the forums.

My Prime95 notes from 5+ years ago, slightly edited to insert some i7 info below.

I bought an i7 on Day 0 when it came out. Notes on that, including RAM info and testing: http://www.ocforums.com/showthread.php?t=595403



To test the stability of overclocked CPU, download the latest bug fixed version of Prime95:
http://www.mersenne.org/freesoft.htm

Double click on PRIME95.EXE to start the program.

Just Stress Testing (if prompted) > OK >
Options > Torture Test > Blend (if prompted) > OK

Number of torture test threads to run should be set to the number of CPU cores. However, Prime95 number of Torture Test threads should be 8 for the four core i7 CPU, not 4 like with the older CPUs.

The i7 runs hot. When running the Prime95 Torture Test for the old Athlon XP, alarm bells went off when the temperatures zoomed past 60° Celcius but I understand realistic OC threshold is now raised toward 90° for max stress when it comes to the i7 CPU.

Prime95 number of Torture Test threads should be 8 for the i7 CPU, not 4 like with the older CPUs.


The program should not give any errors.
It may be necessary to run the program 12-24 hours to make sure an overclocked system is stable (no program errors displayed).


If you get errors only after several hours, this is a result of slight instability because the system is running with little or no margin. It's stable enough to boot and to be moderately stressed, but as soon as the system is under enough load to go over that critical point, it may freeze. To be 100% stable, Prime95 should run 12-24 hours without any errors.

The point of testing is to see if you get errors or not thus testing the stability. The meaning of errors themselves is not as important.


Running Prime95 Torture Test for 5 to 30 minutes is enough to get a feeling about general stability. If it seems to be stable, increase the FSB (with 0.025V Vcore increase if needed), or increase the multiplier by 0.5.

Reboot and run Prime95 Torture Test for 5 to 30 minutes and repeat this until the Program displays errors.
It is then time to back down and repeat the Torture Test until there are no errors for at least 12 hours.

_____________________
Intel i7 920 [211] BCLK x 19 = 4.0 GHz @ [1.4500] CPU Voltage & [1.35000] QPI/DRAM Uncore Voltage, Batch 3836A394
3 x 1GB G.SKIL DDR3 1333 (PC3 10666) [DDR3-1691MHz] 10-10-10-24 @ 1.64 DRAM Bus Voltage
ASUS P6T Deluxe v.1 [LGA 1366 Intel X58] BIOS 1606
Thermalright Ultra-120 eXtreme 1366 RT with 120mm Scythe S-Flex F fan
ASUS EAH4850 TOP Radeon HD 4850 512MB @ 680 MHz GPU & 2100 MHz Memory
Antec nine hundred case, two front 120mm fans, one back 120mm Fan, one top 200mm fan
Corsair CMPSU-750TX 750W

 

[Four20]

Thanks for the response c627627. Out of 2 highly suggested forums that I posted my questions on(here and TomsHardware.com), you're the only person to reply with some detailed information.

90C are you serious? I read that anything 80C and over is bad and can damage the CPU. . .but it's best to keep it below 75C if possible.

So you're saying I should load fresh bios details, then focus increasing the FSB/BLCK or Multipler? I thought I should set it as a desired multiplier(what is your suggestion?) and then start increasing the FSB/BLCK.

Then when I start to get errors or it won't boot, I should then start to increase the CPU core voltage until it boots and is stable again. . .then I should start increasing the FSB/BLCK until it errors or won't boot. Then rinse and repeat, making sure not to go over 1.35V on the CPU core voltage.

Is this correct?

I have also read about tweaking the PLL and VTT can help improve stability. Is this true? IF so, when should I increase these during my testing?

Thanks again!

 

[c627627]

First of all, Overclockers is by far the best computer forum, I never buy anything without checking here first and I get unbelievably helpful answers to even non-computer related questions, every time.


Yeah... 90° C and that's under extreme stress which is hopefully somewhat temporary as things go . We're talking about i7 which does run hotter, things are nor what they used to be with previous CPU generations.


I'm saying find out your max BCLK by lowering the multiplier first, then adjust the multiplier up to match the hopefully higher rather than lower BCLK.


Yes, higher voltage + decent heatsink should get you 4 GHz + unless you're unlucky with the chip.

Max voltage? You can see in my sig that I went a little extreme so .

I ended up leaving CPU PLL Voltage and many other settings on Auto when I reached 4 GHz and so should you fail to do that, only then start tweaking them... let me know if changing other settings stabilized anything that was previously unstable.


_____________________
Intel i7 920 [211] BCLK x 19 = 4.0 GHz @ [1.4500] CPU Voltage & [1.35000] QPI/DRAM Uncore Voltage, Batch 3836A394
3 x 1GB G.SKIL DDR3 1333 (PC3 10666) [DDR3-1691MHz] 10-10-10-24 @ 1.64 DRAM Bus Voltage
ASUS P6T Deluxe v.1 [LGA 1366 Intel X58] BIOS 1606
Thermalright Ultra-120 eXtreme 1366 RT with 120mm Scythe S-Flex F fan
ASUS EAH4850 TOP Radeon HD 4850 512MB @ 680 MHz GPU & 2100 MHz Memory
Antec nine hundred case, two front 120mm fans, one back 120mm Fan, one top 200mm fan
Corsair CMPSU-750TX 750W

http://www.ocforums.com/showthread.php?t=595403

 

[Four20]

I just took the PLL Voltage to 2.0 and ran Prime95. Workers 5 and 6(the ones that always error first) stopped after 5 minutes instead of 10 seconds(like before). but this pushed the temp to 79, which I thought 80 was getting too much.

So 90 is really ok? I know it's a newer chip and can handle more, which made sense when my roommate said his max is like 60 or something.

I will wait until the heatsink and 750W PSU come in(tomorrow) before trying to get to my 4Ghz/200FSB goal

 

[c627627]

Woe, don't be overclocking w/o excellent cooling now

Yes, in my opinion it is OK for i7 to go into 80°'s C under max Prime95 stress.