Hi all,

 

I've spent a number of weekends learning about and trying to overclock my i7-4700k. I believe I finally have a stable overclock of 4.2 Ghz. But as I'm very new to overclocking CPUs, I just want to make sure that my system is running at safe temperature ranges; I don't to damage the system in the long run just to jump from 3.5 to 4.2ghz. Does anyone use a tool while running FSX to monitor their temps? So far, I've been using HWMonitor and just switching between FSX and that program or using FSX in window mode and having it side by side with HWMonitor. Last night I set up a flight and it fly on auto-pilot for about 40 mins. I checked in on HWMonitor and the max temp column read 68C. However, when I put FSX side by side with HWMonitor tonight while doing a flight it seemed to hang mostly in the upper 50s.

 

I did a second test using my CPU at stock speeds at 3.5GHz. HWMonitor showed a max temp of 49C but I only ran that test for 5 or 6 minutes. I was hoping to just get an idea of where I stood with this OC. When I ran Prime95 for two hours I hit a max temp of 92C but mostly hovered in the high 70s to low 80s.

 

I would just like to get an idea of where I stand with this overclocked system, especially in regards to the temperature. If anyone could give me their thoughts I'd sincerely appreciate it.

 

On a side note - does anyone notice a difference between 3.5 and 4.2ghz while playing FSX? I was trying to switch between the two, but I couldn't really get an idea of the difference without having them side by side.

 

Again, I truly appreciate your time in helping me out. I've been at this system-build for many weeks now and just want to finalize this last item so I can start to fully enjoy this system. Thank you again!

Those temps are just fine, my i7 is running at 4,3GHz and it never exceeds 60°C when flying. Haswell cpu's tend to heat up quickly and anything in the 80°C range shouldn't harm your processor as long as you don't run it 24/7 at that temp but since FSX isn't that hard on temps it's no issue at all. HW Monitor is a good software. You should get better performance with your overclock though, I noticed a boost with my system, it's not huge but noticeable. Did you try the same scenario with and without OC? Also what is your cpu voltage set at? Are you using an aftermarket cooler?

Some threads here give a rough indication of an improvement of 1 frame per second for every 100Mhz that you overclock. Hardly scientific but how small the improvements are in practical application.

 

The I7 4770 will run at default speeds between 3.5 and 3.9 Ghz with no overclock applied, so an overclock to 4.2 Ghz will give you theoretically an increase of around 3-4 FPS. Does not sound like much but it can make a visible and tangible difference.

 

For this reason, it makes little sense to spend hours trying to get your overclock up by another 100-200 MHz and then on top of that trying to deal with heat and stability issues unless you are doing it simply for the achievement - not going to have a huge benefit in the game.

 

Depending on your motherboard, you can easily get a 4.2GHz or a 4.3 GHz overclock while still letting the system set the voltages automatically. Just a couple of clicks in the BIOS. Having the unlocked "k" series CPU helps. FSX will never test the CPU to the limits that Prime95 does. An aftermarket cooler is a good way to go as the stock Intel cooler for the 4770 is a littler on the light side. I run a closed loop water cooler H100i from Corsair which is not particularly costly and can be installed in a matter of minutes - provided your case has sufficient space to accommodate the radiator and fans.

Some threads here give a rough indication of an improvement of 1 frame per second for every 100Mhz that you overclock. Hardly scientific but how small the improvements are in practical application.

 

No, that's not correct. It's linear, think in terms of percentages.

 

If you overclock by 10% you will get a 10% increase in frame rate.

 

3.5 to 4.2 will give you a 20% increase in frame rate. So if your frame rate was 30 before, it will be 36.

 

To the OP, are you using a fixed voltage, or an adaptive voltage?

 

4.2 is a minimal overclock, in fact at such a low overclock, [if it's an Asus board] it's simply a case of flipping the TPU switch on the motherboard, for an easy and painless overclock.

 

As Max said, what kind of a cooler are you using? And how did you overclock, with a motherboard software, or manually through the UEFI?

To provide some additional information:

 

PC parts:

• Mother Board:ASRock Z87 Extreme6 ATX LGA1150
• CPU Cooler: Corsair H100i

 

OC Settings:

CPU All Core Ratio 42
CPU Cache Ratio 35
Vcore adaptive voltage 1.300
Vcore voltage additional offset Auto
CPU Cache Override Voltage Auto
CPU Cache Voltage Offset Auto
System Agent Offset Auto
Fixed Voltage 1.850

 

EDIT: Just to clarify. I originally had Vcore set to override and at 1.300. However, when I switch it back to adaptive mode, the value reads Auto.

 

 

Again I sincerely appreciate all the help and guidance!

Hmm I would set a fixed value for vcore. That doesn't mean adaptive voltage is a bad thing, but if I remember correctly, when the cpu is stressed vcore can go up pretty high and produce high temps. Mine is set to 1,2V and it runs stable in prime without a hassle, even with HT on. For a watercooler the temps are a bit high imo. If you haven't tried yet, lower vcore to 1,2 and do a stress test. If your system crashes, do a small increment and test again. Repeat this until you found a stable value and you should be fine.

Hmm I would set a fixed value for vcore. That doesn't mean adaptive voltage is a bad thing, but if I remember correctly, when the cpu is stressed vcore can go up pretty high and produce high temps. Mine is set to 1,2V and it runs stable in prime without a hassle, even with HT on. For a watercooler the temps are a bit high imo. If you haven't tried yet, lower vcore to 1,2 and do a stress test. If your system crashes, do a small increment and test again. Repeat this until you found a stable value and you should be fine.

 

Thanks armchair_pilot I will work on that this weekend. I had read somewhere else that fixed voltage should be 0.55 higher than the vcore. Is that true?

 

I guess what I get most confused about is with the temps. I've had people tell me my temps are fine and others say they are too high and should run in the 60s under load. This sometimes conflicting information has had me going in circles that last several weekends. I really appreciate any guidance or direction I receive. 

No problem. I'm not sure about fixed voltage, I always leave it at default 1,9V. I'm no expert there

 

If you had an air cooler I would say the temperatures are fine, but you should achieve better temps with your cooler unless you have HT turned on or a bad chip. HT on makes a difference of +- 20°C for me when stress testing, in addition FSX performance drops...

Hmm I would set a fixed value for vcore. That doesn't mean adaptive voltage is a bad thing, but if I remember correctly, when the cpu is stressed vcore can go up pretty high and produce high temps.

Adaptive voltage is fine. Until... you run synthetic stress tests like Prime95 or IBT etc. When you do, an additional voltage is automatically added, whether you like it or not, that can push the temps way too high.

 

Probably why the OP found his temps peaking at 90 [too high] running Prime.

 

The moral of the story, is that if you wish to run adaptive, don't run synthetic stress tests.

 

If you do want to run synthetic stress test, use a fixed voltage.

 

 

I guess what I get most confused about is with the temps. I've had people tell me my temps are fine and others say they are too high and should run in the 60s under load. This sometimes conflicting information has had me going in circles that last several weekends. I really appreciate any guidance or direction I receive.

 

 

 

Running FSX, or any other real world application, 50, 60, or even a tad higher is fine. However, when running synthetic stress tests, I wouldn't advice allowing temps to exceed 80-85 degrees.

 

 

And remember what I said... heed the warning regarding running synthetic stress tests with an adaptive voltage.

Thanks for the feedback. I apologize for not being more clear - when I run tests like Prime95 I swtich vcore back to override mode; I only leave it in adaptive mode for day-to-day use.

 

I turned HT off and ran Prime95 again (with vcore in override mode). So far, my temperatures are a few degrees lower - maxed temp momentarily spiked to 88C but it seems to mostly be hovering in the mid 70s. Tonight I will turn vcore back down to 1.2 and bring it up in .01 increments until I find something that works. I think I'll also trying setting my fixed voltage to 1.9 and once I find a stable vcore, try bringing the fixed voltage down by .01 increments until I find the right combination.

 

I really appreciate you guys taking the time to help me out and give me some clarification. I'll post back here tonight after I spent a few hours tweaking my OC to give an update on my progress. I'm really excited to finally start enjoying FSX!

Just one additional rookie question: for controlling temps is it better to have a lower vcore or a lower fixed voltage?

I've been working on this all day. I think I've got my vcore down to 1.21 and I've left my fixed voltage at 1.9v for now. Right now my temps are staying right around the low 70s for the most part while running Prime95 (there's an occasional spike up to 80 that lasts for just 1 second or so). I'm much happier with these results so far and will be doing some more fine tuning tomorrow. I'll post back here if I run into any issues.

 

Again, many thanks for all the help that's been provided so far. I sincerely do appreciate it.

Lower vcore is always better. Glad you found a good setting B)

 

Lower vcore is always better. Glad you found a good setting B)

 

 

Thanks! Here are the values I locked in at:

 

CPU All Core Ratio 42

CPU Cache Ratio 35

Vcore override voltage 1.210 *set to adaptive after testing

Vcore voltage additional offset Auto

CPU Cache Override Voltage Auto

CPU Cache Voltage Offset Auto

System Agent Offset Auto

Fixed Voltage 1.900

 

And my temps are at:

 

Prime95 high 75 C

Prime95 avg 65-70 C

FSX high (after 30 mins of flying) 64 C

FSX avg (after 30 mins of flying) 55-63 C

I would imagine you could increase your CPU Cache Ratio min and max to 39 at least if you are going for a manual overclock of 42. It is my understanding that you want this number to be closer to your core ratio, not more than it though. With a Core ratio of 42 you can start with 39 on the CPU Cache ratio.

 

If you Google "Haswell 4.8Ghz on air - Building a Haswell System", there is a very detailed guide courtesy of "Nick N" (a long but informative read, even for first timers) He uses an Asus motherboard but much of the logic and settings will be the same on your board.

 

With a 'light' overclock of 42, you are safe with adaptive V Core.  A V-core override of 1.18 should get you stable - but there are so many variables that makes it impossible to copy settings from one system and expect that they will work on another.