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Crosshair V Formula & AMD FX-8150 CPU Overclocking Guide

Level 15

AMD FX CPUs overclock well if you know the right settings, and the CrossHair V Formula motherboard is ROG’s 5th Gen AMD hardware, so the team behind it has plenty of experience under their belts. As supplementary reading, we strongly recommend you reading a very good article titled the CrossHair V Formula Oveclocking BIOS Guide, written by Raja.

With that in mind, I am not going to go into too much depth about those aspects here, instead I’ll be aiming at getting you directly up, running and overclocked by providing clear steps to follow in order to achieve a solid all round overclock with your new AMD FX processor. From here, and with Raja’s guide, you experiment to fine tune your system and learn more.

The AMD FX Processor: AMD FX-8150 Specifications

Native Frequency: 3.7GHz
Turbo Frequency: up to 4.2GHz
Manufacturing process: 32nm
Number of cores: Eight physical
Memory controller: Dual-channel DDR3
Cache: 8 x 16KB L1 data, 4 x 64KB L1 instruction, 4 x 2MB L2, 4 x 2MB L3
Socket: AM3+
Thermal Design Power (TDP): 125W
Features: SSE, SSE2, SSE3, SSE4a, SSE 4.1, SSE 4.2, 256-bit AVX, AESNI, PCLMULQDQ, AMD64, Cool’n’Quiet 3.0, AMD-V, MMX, FMA4, XOP

The Motherboard: ASUS CrossHair V Formula

Chipset: AMD 990FX
CPU Socket: AM3 and AM3+ processors including Sempron, Athlon II, Phenom II and FX
Memory support: 4 slots, max 32GB DDR3
Expansion slots: four 16x PCI-E 2.0 slots (two 16x or one 16x, two 8x and one 4x), one PCI, one 1x PCI-E
Sound: 8-channel HD Audio via Creative SupremeFX X-Fi 2
Networking: Intel 82583V Gigabit Ethernet
HTT frequency overclocking range: 100 – 600MHz; max voltages, CPU 2.1V, CPU NB 1.875V, Chipset 2V, HT 2V, RAM 1.8V, Southbridge 1.8V
Ports: 7x SATA 6Gbps, 1x PS/2, 14x USB 2, 6x USB 3, 2x FireWire, LAN, 4x surround audio out, line in, mic, optical S/PDIF out, eSATA 6Gbps
Dimensions (mm): 305 x 244 (ATX)

And The Rest:

CPU Cooling: Mainstream performance air cooler
DDR3 Memory: Geil 2GB x 2 DDR1600MHz
Graphics Card: ASUS Radeon HD 5870 2GB
Power Supply: Corsair HX850


It is up to the individual to select the CPU/Memory stress test tool of choice. But please be aware of the following, previously on AMD platforms Prime95 was the most stressful tool, and it historically stressed the northbridge and memory more than Linpack, however the gap has narrowed between the two. The difference between the two outcomes for maximum Overclock using Linpack and Prime95 was less than 100MHz at the same settings. Remember a stability tests is an artificial exercise and the proof of the pudding is in the eating if you never crash your system.

LinX download
Prime 95 download
Memtest download

Using a windows based overclocking utility makes the whole overclocking process so much simpler and saves time if you are in a hurry to play with your new toys. You can also use ROG Connect if you have a spare rig, or a Bluetooth device such as a smart phone or tablet. Personally I really like the ROG Connect utility and can recommend it to anyone. The only problem that I noticed is the temperature reading can differ between the board and the ROG Connect by a margin of difference of nearly 10C, now that could just be because the motherboard OS based utility and the ROG software is not yet optimized for the AMD FX. Not critical, but worth noting.

AMD OverDrive download
ROG connect download

A easy work round to changing multiplier in OS is to simply use k10stat, the update will be available soon.

K10 Stat ( when updated )

Monitoring utilities are a must and the reviewer pack I have linked too is very handy as a all-in-one download for AMD FX.

CPU-Z AMD FX reviewer pack download.


Cinebench and Hyper Pi are the 2 main applications that I use for a rough and ready test just to find the upper limits of the system and get a ballpark figure for voltages needed. Plus they help me get an idea on how to approach the higher clocks. It’s always handy to run benchmarks like this throughout testing to make sure your performance is going in the right direction. Think of it as a auto-regulation feedback loop.

Level 15
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.

Level 15
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.


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.

Level 15
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.


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.

Did you do a lengthy Prime95 test? I found that even with "stable" overclocks in the 4.5ghz+ range, I would see cores drop out after a few hours. I know this would not be indicative of "normal" use, but it's something to be worried about if one is overclocking for the purpose of doing Folding@Home or similar.

Can you elaborate on what you consider "stable"? Because at these settings and with some of my own experimentation, I find them less than totally stable.
Intel i7-4790k @ 4600 (100x46) 1.265vc (w/ Corsair H100 & Gelid GC-Extreme)
ASUS Maximus VII Hero
Mushkin Enhanced Red/Blackline 4x4GB @ 2000Mhz
MSI Lightning Radeon 6970 @ 940/1375
Mushkin Enhanced Chronos Deluxe 120GB Sata III
Seagate Barracuda 7200.12 1TBx2 in W7 Raid 1
Corsair Obsidian 800D w/ Corsair AX850 PSU

Level 8
Well its not stable if even one core stops working at any given time.
Last day my prime stopped (1core) after 5hours mark of blend and so i need to tweak it more.
To me only prime dont cut it, but after 12h of prime i move to secend test. as i dont run my system 24/7.

Thanks for the Guide!
I look in to it at better time for more clues what i may have don wrong...
CPU: AMD FX-8150 MB: ASUS Crosshair V Formula DDR3: 2x4GB G.Skill Sniper DDR3-1866
GPU: ASUS 7970 SSD: 4x Corsair F3 120GB @ Raid0 PSU: SF Golden Silent 500W OS: W7 Ultimate 64bit

Level 18
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.

Level 12
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.

Hi, I would like to thank you for this thread.
I am having trouble with the Bulldozer to getting to work at it's native 3.6 GHz frequency : it down-clock itself frequently to 7 multiplier (1.4GHz) despite the low temps ( 34 degrees Celsius) and despite sometimes the demand (gaming) which slows my gaming very much.
I have disabled power management and cool and quiet from bios, and double checked at the Asus AI II suite EPU menu (high performance profile selected), double checked power plan of windows 7 (high performance selected), disabled Turbo using AMD overdrive (couldn't find any alternate way to disable it) and kept all other bios settings to default.

When I checked voltages I found Vcore fluctuating very much concomitantly with slight CPU-NB voltage fluctuations and CPU self down-clocking to X7
Even though I set the bios value to default most of them, CPU still manages to overclock itself @ 19.5 !
I have no grasp over the DIGI-VRM thing but I set it to " optimized" through AI II suite

I previously had AMD phenom II x 4 955 BE which I had no issue keeping it at a stable NATIVE or overclocked frequency.

;):cool: SOLVED : C6 state disabled no more AMD CPU throttling
Thanks for your time