Let the Overclocking Begin
The first step is to familiarize yourself with the BIOS. It is a good idea to shut off a few things, mainly power saving and CPU Turbo but if there’s anything else you aren’t using (audio and LAN etc) you can go ahead and disable those too.
Important: Switch AI Tuner to manual to unlock the HTT.
Another thing to take note of is the profile settings and the GO buttonfunction.
TIP: You’re likely be trying a lot of different settings, some will be successful other will not. Get into the habit of using the OC Profiles to save them so when you clear CMOS you have most of the settings already setup.
Initial testing and the system limits
A good place to start things off is by testing the ram and northbridge whilst leaving the processor at safe clocks so it’s out of the equation. That isolates a couple of variables so that if any problems occur, we have a clear idea of what the problem is.
CPU-NB voltage
Bulldozer does not scale in the same way as AMD’s Deneb and Thuban cores, my gut feeling is that temps and silicon quality are going to play a bigger role than voltages. For example with my processor sample I could boot the 2600 strap with stock cpu-nb voltage and couldn’t move up a strap regardless of voltage. There are also a few unsupported straps on this board that need fixing with a bios update so that might hamper your HTT overclocking until released.
A perfect application is hyper pi to give the NB and Memory a quick workout rather than prime 95 or memtest which take much longer, as we are just looking for ballpark figures at this point in the process. I used the 1866 divider as the 2133 divider wasn’t reading ram clocks in windows, something which I thought was important for this exercise.
Northbridge (NB) voltage
NB voltages, not to be confused with CPU-NB voltage, helps with HT stability at higher frequencies (2200+). If you have a lower speed kit then you probably do not have to worry about it. With the set I was using I found 1.175V to be the sweet spot and helped me gain a few clicks, much over 1.2V and it started to go backwards so keep that in mind and find out what works best for your ram.
CPU-NB voltage
Although it didn’t help cpu-nb clocks as much as I would of liked or expected, CPU-NB vlotage made a noticeable difference to HTT clocks. For example at 267 base clock I was using up to 1.3V on the CPU-NB. Again too much voltage and you are going to see backward scaling or crashes with your system. This phenomenon seems to be consistent with all aspects of overclocking the Bulldozer. Setting everything to the max is not a viable option with Bulldozer. Incremental step by step increases provide the best results.
The first step is to familiarize yourself with the BIOS. It is a good idea to shut off a few things, mainly power saving and CPU Turbo but if there’s anything else you aren’t using (audio and LAN etc) you can go ahead and disable those too.
Important: Switch AI Tuner to manual to unlock the HTT.
Another thing to take note of is the profile settings and the GO buttonfunction.
TIP: You’re likely be trying a lot of different settings, some will be successful other will not. Get into the habit of using the OC Profiles to save them so when you clear CMOS you have most of the settings already setup.
Initial testing and the system limits
A good place to start things off is by testing the ram and northbridge whilst leaving the processor at safe clocks so it’s out of the equation. That isolates a couple of variables so that if any problems occur, we have a clear idea of what the problem is.
CPU-NB voltage
Bulldozer does not scale in the same way as AMD’s Deneb and Thuban cores, my gut feeling is that temps and silicon quality are going to play a bigger role than voltages. For example with my processor sample I could boot the 2600 strap with stock cpu-nb voltage and couldn’t move up a strap regardless of voltage. There are also a few unsupported straps on this board that need fixing with a bios update so that might hamper your HTT overclocking until released.
A perfect application is hyper pi to give the NB and Memory a quick workout rather than prime 95 or memtest which take much longer, as we are just looking for ballpark figures at this point in the process. I used the 1866 divider as the 2133 divider wasn’t reading ram clocks in windows, something which I thought was important for this exercise.
Northbridge (NB) voltage
NB voltages, not to be confused with CPU-NB voltage, helps with HT stability at higher frequencies (2200+). If you have a lower speed kit then you probably do not have to worry about it. With the set I was using I found 1.175V to be the sweet spot and helped me gain a few clicks, much over 1.2V and it started to go backwards so keep that in mind and find out what works best for your ram.
CPU-NB voltage
Although it didn’t help cpu-nb clocks as much as I would of liked or expected, CPU-NB vlotage made a noticeable difference to HTT clocks. For example at 267 base clock I was using up to 1.3V on the CPU-NB. Again too much voltage and you are going to see backward scaling or crashes with your system. This phenomenon seems to be consistent with all aspects of overclocking the Bulldozer. Setting everything to the max is not a viable option with Bulldozer. Incremental step by step increases provide the best results.
Ram Voltage
Every kit is different and every kit is different on each different platform. In this instance, having used the same set of ram on Llano and finding the ram scaled well right up to 1.76 volts, I was surprised to find that with Bulldozer the ram would do more with less voltage and indeed become unstable with more voltage applied. In this instance 1.69v was used for the final round of testing which I would be happy to use 24/7.
Warning: I found that Vdimm over volts quite a lot on my board, might not be the case on others. I found that 1.7125 set in bios, 1.733 read via software in windows and 1.745 on the read point. Not ideal but as long as you are aware of the disparity it is workable. So keep monitoring the readings and note the differences between what you set in bios.
HTT Overclocking
While a HTT of 270 seems to be the upper limit under ambient it might be worth attempting a reasonable HTT Overclock. In testing I found it reasonably difficult to Overclock past 4.8GHz using the multipliers only. I needed HTT to get into the 5GHz range. If using HTT to Overclock it makes good sense to use memtest just to be on the safe side.
Memory OC
If you are a bit new to this then the ram profiles in the timings menu are a great place to start, they are tuned more for frequency and should be good for around 2400 on most half decent PSC modules with reasonable voltages, it may be worth tightening up the trfc a little as I have found they are set very loosely at 300ns by default.
For example here is 2400+ without much fuss and without going near the drive strengths, which is quite impressive. AMD seem to have a lock on memory clocking.
As you can see the voltage setting is a quite high. Here is something a bit more realistic for daily use.
CPU OC
Cinebench is a good starting point to give you an idea of your chips capabilities. Your Overclock will almost always be higher than your maximum stable Overclock. None the less to get an idea of voltages etc that are needed it’s a good starting point.
I have no idea of safe voltages as yet, I was not able to find the AMD white paper but I presume the temp limit is still in the low 60′s and that’s where I’m trying to keep it. So let temperature be your guide. As with the previous generations of processors from AMD temps play a huge role in stability so it is best to try and keep temps less than 60C. As was mentioned earlier it was difficult to achieve higher Overclock without touching the HTT so you have to move it off 200.
Every kit is different and every kit is different on each different platform. In this instance, having used the same set of ram on Llano and finding the ram scaled well right up to 1.76 volts, I was surprised to find that with Bulldozer the ram would do more with less voltage and indeed become unstable with more voltage applied. In this instance 1.69v was used for the final round of testing which I would be happy to use 24/7.
Warning: I found that Vdimm over volts quite a lot on my board, might not be the case on others. I found that 1.7125 set in bios, 1.733 read via software in windows and 1.745 on the read point. Not ideal but as long as you are aware of the disparity it is workable. So keep monitoring the readings and note the differences between what you set in bios.
HTT Overclocking
While a HTT of 270 seems to be the upper limit under ambient it might be worth attempting a reasonable HTT Overclock. In testing I found it reasonably difficult to Overclock past 4.8GHz using the multipliers only. I needed HTT to get into the 5GHz range. If using HTT to Overclock it makes good sense to use memtest just to be on the safe side.
Memory OC
If you are a bit new to this then the ram profiles in the timings menu are a great place to start, they are tuned more for frequency and should be good for around 2400 on most half decent PSC modules with reasonable voltages, it may be worth tightening up the trfc a little as I have found they are set very loosely at 300ns by default.
For example here is 2400+ without much fuss and without going near the drive strengths, which is quite impressive. AMD seem to have a lock on memory clocking.
As you can see the voltage setting is a quite high. Here is something a bit more realistic for daily use.
CPU OC
Cinebench is a good starting point to give you an idea of your chips capabilities. Your Overclock will almost always be higher than your maximum stable Overclock. None the less to get an idea of voltages etc that are needed it’s a good starting point.
I have no idea of safe voltages as yet, I was not able to find the AMD white paper but I presume the temp limit is still in the low 60′s and that’s where I’m trying to keep it. So let temperature be your guide. As with the previous generations of processors from AMD temps play a huge role in stability so it is best to try and keep temps less than 60C. As was mentioned earlier it was difficult to achieve higher Overclock without touching the HTT so you have to move it off 200.
Putting it all together
Now we have a rough idea of what the system is capable of it’s time to put it all together. This is the most challenging part, and the most fun. What I suggest is to drop down the memory and the NB for now. As it is a little harder to combine a high memory and Northbridge Overclock with a CPU Overclock, normally there needs to be a little give and take to reach a stable balance between the two.
Around 4.8 GHz could be the sweet spot with this processor I think, as I had set my voltages within a range of just above the default turbo VID of 1.4 to under 1.5 with a pleasingly high Overclock on the ram, while still managing my temps keeping them touching on 50’c under load. This would be fine for as a daily rig
Bearing all that in mind and finding a good balance between the two I ended up with this OC.
Unfortunately 5ghz on air was not possible with a balanced Overclock and suitable temperatures, the temperatures were simply too high. Maybe on a top end Air Cooler 5GHz will be doable. Certainly 5GHz is a proposition with water cooled systems. Early testing has indicated that the gains we’ll see from dropping those few degrees is going to be much higher than what was had from the Phenom II.
Interpreting Crashes
Unlike the Phenom II interpreting what caused crashes was less clear cut. With Bulldozer I haven’t had a single hard crash which required a power cut to get the system to post again. Therefore I would suggest that no change to the current protection settings in the bios are made, doing so is an unnecessary risk and dangerous on ambient cooling.
Most common error is machine check errors and similar.
BSOD that do not have a memory dump all seem to be CPU related, either to much or to little voltage.
Those BSOD with memory dump trace back ot either Northbridge or the memory, with lock ups similarly being memory or Northbridge related.
Interestingly after a lock up your reset button might not work a lot of the time (9905 bios) to resolve simply hold down the start button and wait for it to shut off. You are good to go after that.
Occasionally VCore won’t apply after a crash. This will cause another crash under load (and will usually fail before it loads OS). It is best to either check VCore in bios or to power down completely to resolve.
Tweaking
Now you have a solid OC you can start to tweak it to get those few extra MHz or just for the fun of it, raising the HTT one notch at a time may be a good way to go or you could try tightening timings, it is up to you the secret is just have fun with your system. This board really is a dream to use, it doesn’t get much easier. If you are able to use ROG connect then I really can recommend that you do so. For example, if you have a rounding error during your stability testing with Hyper Pi the ROG connect allows you to fine tune voltages on the fly and therefore try again immediately without having a resource greedy application running on the system you are overclocking.
After I was confident it was stable at the above settings with the memory Overclock rock solid I tried pushing the platform a little further.
A tad more voltage was needed for the processor and that resulted in this Overclock being right on the 60°C limit. Which was just too high for any prolonged use as a 24/7 system.
Wrap Up
There is no one correct way to work out your systems Overclock. I do it this way because it is simple, methodical and relatively quick. The screenshots that I have posted are for my hardware and might not match or be what your processor needs. You might require less voltage or possibly more. No two processors are the same as we all know. This is why I am a fan of the kind of methodology I described above and which I use to determine an Overclock. It helps me isolate where the Overclock is weakest with the least amount of fuss and hassle. If you follow the steps contained in this guide then I am confident you will easily achieve what are the optimal overclocking settings for your AMD FX and ROG Crosshair V motherboard. Enjoy your overclocking.
Now we have a rough idea of what the system is capable of it’s time to put it all together. This is the most challenging part, and the most fun. What I suggest is to drop down the memory and the NB for now. As it is a little harder to combine a high memory and Northbridge Overclock with a CPU Overclock, normally there needs to be a little give and take to reach a stable balance between the two.
Around 4.8 GHz could be the sweet spot with this processor I think, as I had set my voltages within a range of just above the default turbo VID of 1.4 to under 1.5 with a pleasingly high Overclock on the ram, while still managing my temps keeping them touching on 50’c under load. This would be fine for as a daily rig
Bearing all that in mind and finding a good balance between the two I ended up with this OC.
Unfortunately 5ghz on air was not possible with a balanced Overclock and suitable temperatures, the temperatures were simply too high. Maybe on a top end Air Cooler 5GHz will be doable. Certainly 5GHz is a proposition with water cooled systems. Early testing has indicated that the gains we’ll see from dropping those few degrees is going to be much higher than what was had from the Phenom II.
Interpreting Crashes
Unlike the Phenom II interpreting what caused crashes was less clear cut. With Bulldozer I haven’t had a single hard crash which required a power cut to get the system to post again. Therefore I would suggest that no change to the current protection settings in the bios are made, doing so is an unnecessary risk and dangerous on ambient cooling.
Most common error is machine check errors and similar.
BSOD that do not have a memory dump all seem to be CPU related, either to much or to little voltage.
Those BSOD with memory dump trace back ot either Northbridge or the memory, with lock ups similarly being memory or Northbridge related.
Interestingly after a lock up your reset button might not work a lot of the time (9905 bios) to resolve simply hold down the start button and wait for it to shut off. You are good to go after that.
Occasionally VCore won’t apply after a crash. This will cause another crash under load (and will usually fail before it loads OS). It is best to either check VCore in bios or to power down completely to resolve.
Tweaking
Now you have a solid OC you can start to tweak it to get those few extra MHz or just for the fun of it, raising the HTT one notch at a time may be a good way to go or you could try tightening timings, it is up to you the secret is just have fun with your system. This board really is a dream to use, it doesn’t get much easier. If you are able to use ROG connect then I really can recommend that you do so. For example, if you have a rounding error during your stability testing with Hyper Pi the ROG connect allows you to fine tune voltages on the fly and therefore try again immediately without having a resource greedy application running on the system you are overclocking.
After I was confident it was stable at the above settings with the memory Overclock rock solid I tried pushing the platform a little further.
A tad more voltage was needed for the processor and that resulted in this Overclock being right on the 60°C limit. Which was just too high for any prolonged use as a 24/7 system.
Wrap Up
There is no one correct way to work out your systems Overclock. I do it this way because it is simple, methodical and relatively quick. The screenshots that I have posted are for my hardware and might not match or be what your processor needs. You might require less voltage or possibly more. No two processors are the same as we all know. This is why I am a fan of the kind of methodology I described above and which I use to determine an Overclock. It helps me isolate where the Overclock is weakest with the least amount of fuss and hassle. If you follow the steps contained in this guide then I am confident you will easily achieve what are the optimal overclocking settings for your AMD FX and ROG Crosshair V motherboard. Enjoy your overclocking.
thanks MarshallR .. i thought i had seen the CrossHair V from every possible angle..
and i was wrong ... excellent.
The announcement of the 4.2 makes this even more exciting.c.
and i was wrong ... excellent.
The announcement of the 4.2 makes this even more exciting.c.
What do you think of Intel Burn Test as a stress test? On my old forum some of the fellows were saying it was much more stressful than prime and some of the other tests as well. I have no clue myself. I don't use AMD overdrive to test. It always crashes on me. Well at least my last two motherboards (CrosshairIII w/PII965 and M3A78-T w/ PII940) so I just don't bother with the stresstesting part of it. I just use it to monitor my temps and the like.
Being ingnorant and ingnored one post at a time.
Being ingnorant and ingnored one post at a time.
