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Introduction
This is my first post on this very nice forum so please bear with me
So hello to everyone and let's hope this topic will be of use to some of you. To start off, I have a love for overclocking my gear and like a half a year ago, I got a Gygabyte X38 DS5 board. It appeared to be a pain in the ass to overclock, it would never be really stable. In the end, I changed everything back to stock and it still remained sort of unstable. And trust me - it was the board. Cooling wasn't an issue.
A week ago I searched for a nice replacement board, and reading around, I was quite impressed with the XFX N790i board. I also got aware of the "data corruption" troubles this board would have. Well, two days ago I picked up my prize and began to play with it. Through this topic I would like to share my results and thoughts on overclocking this board. I will also make a note on the data corruption. So here goes...!
The Rig
The current rig now consists of the following:
Overclocking, the CPU and Mobo
It is a great board, but as with any great board, you'll need to find out how to treat it. To start off with the CPU, I know mine was able to deal with a 1800ish FSB maximum. I left all the board's settings on auto, except for the EPP2.0 setting that would unlock the FSB controls. I felt bold, and set the FSB to 1600 and the multi to 7 without configuring anything else.
As the board rebooted, it hicked up a few times, apparently not wanting to complete the POST. As it appeared, the board has a nifty feature that attempts your new settings, and if the board thinks it ain't going to work it tries 2 more times. On the 3rd reboot time, the board enters safe-mode, defaulting CPU and memory speeds. It still retains all your settings though. In my experience, it works better than ASUS's CPR, which is a similar feature.
So here I was. Why wouldn't the board just complete the POST at a 1600FSB? I went back into the BIOS, looked at the auto adjusted voltages and saw most being green. Meaning, the board had upped the majority of the voltages. The CPU voltage to a whopping 1.4v, as well as the FSB voltage and the NB voltage. Well, then I decided to lower the FSB to 1333MHz and saved. Well..! Now the board didn't hickup and I booted straight into windows.
The first benches were not too impressing. Especially the memory bandwith benches. Still, I was puzzles why the board wouldn't do a 1600 FSB. Then it got me thinking. On previous nForce boards I learnt that upping the northbridge voltage anywhere over 1.35V had an adverse impact on overclockability. Don't ask me why, it's what I experienced.
In my quest to find the highest attainable FSB for my Q6600 in combination with this board, I went back to the BIOS and put ALL foltages to stock levels, taking them off of "Auto". The CPU Vcore voltage however, I set to 1.3V as in my experience that is a nice start to have the CPU run at a 1600FSB. After saving the settings, the board continued its post without a hitch, ending up in my Windows XP, seemingly rock-solid. After running some benches and using Prime95 for half an hour just to check short-term stability, I was getting a smile on my face. This brings me to the first guideline for this board:
Do not let the N790 manage voltages. Set ALL voltages to their stock defaults manually. 1.2V for the FSB Voltage, 1.3V for the NB Voltage, 1.5V for the SB. In case of my memory, it was 1.8V stock.
As I have discovered, I never even had to increase the NB voltage or the FSB voltage for that matter. The only voltage you will be modifying is the CPU Vcore voltage. And so I went on with my quest. Eventually, I could get an FSB of 1750MHz on this Q6600, running at around 3ish GHz. However, the Vcore was set to a whopping 1.475V.
While the system was stable, and temperatures not too shocking (62-65 degrees under load), I noticed I was getting into the area where the needed Vcore jumps became to high in relation to the FSB jumps.
Overclocking the Memory
Now it was time to play with the memory. Since this memory was rated 2000MHz @ 1.8V, I knew that the memory would have plenty headroom. I still had the FSB at 1750MHz. And so I set the memory clock to 2000MHz. Well, the rig booted, but then halfway loading Windows, I got a BSoD. No biggy. I restarted the computer. And again, this BSoD. Hmm, now it was time to set everything back to stock, just to be sure. After a reboot, AGAIN this BSoD. So I started to think.. "This must be the data corruption they've been talking about". And so it was. I had to restore a disk image to get started again.
I got back into the BIOS and looked at frequencies. It pretty much looked not right. The memory speed wasn't exactly a whole 2000MHz, but it was a 'broken' number. Obviously there was no suitable FSB:Memory ratio to make the memory speed a clean whole number. I prefer clean, whole numbers. Then you can tell by the numbers that everything is synched properly. Then, I set the memory to the same 1750MHz, and didn't experience any more data corruption. However, after running benches I was unimpressed. Now here a finding regarding memory on this board:
Always use the Unlinked FSB/Memory clock mode! And, always adjust either clocks in such way that they form a solid granularity, where you end up with whole numbers, or nice broken numbers (like 1333.3). Avoid using the exotic division ratios.
Although data corruption is not fun, I really would not attribute this to NVidia or the N790 chipset specifically. And let me tell you why. When you overclock, there is the risk that anywhere in your system, bits may flip. Read instructions may become write instructions. Addresses may point to wrong locations. As you know, Windows XP writes to disk during bootup and on shut-down. If any number of bits change value and get written back to disk, you're screwed. Most of the time you will not even notice datacorruption while overclocking. But it happens, trust me. I have had many boards in the past that exhibited data corruption to the point where the OS would not boot any more. Today's hardware is very delicate. Not increasing Vcore high enough may cause corruption. Unsynchronized clocks may cause timing problems and cause corruption. Too high voltage on components also causes data corruption. So if you wish to overclock this board, or any other board:
Before you begin any overclocking, make a backup image of your OS drive always! Use software like Norton Ghost for this. Then you can always revert back to a working OS in case you ended up with a harmful combination of settings. Once you are done overclocking and found your golden sweetspot, then you can restore your harddrive image. Even if your OS still boots and no apparent corruption is there, do it still, as there definately may be corruption that you won't notice untill later down the road.
Tuning together the Components
As known with the nForce chipset, it begins to insert latency when its FSB is higher than 1600MHz. This, and the fact that I wanted temperature headroom on my CPU (by doing with lower Vcore), I decided to make the 1600MHz my FSB reference. Now it was time to up the multiplier again, and see how fast I could get the CPU. 3.2GHz (8x) was rock solid, at an initial 1.3750v Vcore. The actual Vcore is lower though. The board has a droop of about 0.050V. Load temperatures got up to around 55 degrees maximum. So I gave the 9x multi a whirl, having the CPU run at 3.6GHz. I could get it stable, but it needed a good 1.4750V Vcore which was like 1.4250 effective. Although temperatures weren't extreme with their up to 64degrees, I felt there was too few headrom left as room temperature can increase. And as with determining the max FSB for the CPU, Vcore steps became too big in comparisson to MHz jumps. I decided to go with a rock-solid 3.2GHz @ 1.3250 effective Vcore.
Now it was time to adjust the memory. Since there was a nice divisor that allowed a nice whole number of 2000MHz in conjunction with the FSB speed of 1600Mhz, I tried this out. After running benches, I wasn't too pleased with read performance of barly 8GB/sec. I'm sure that the memory speed between the GPU and Memory would be more than fine. But between the CPU and memory it was disappointing. So, time to now set the memory frequency to a 1600MHz also. At the same time, this allowed me to tighten the timings on the memory as well. From 9-9-9-28-2T all the way down to a very nice 7-7-7-21-1T! Going back to Windows and running the EVEREST memory bench, I now saw this very nice, whopping 10.7GB/Sec on reads, 8GB/Sec on writes and copies. That made me smile big-time. Another conclusion I drew from this:
Try to keep your memory speed the same as your FSB speed (actually twice as fast, as DDR is base x2, and FSB is base x4). This requires the least synchronization efforts by the northbridge. Secondly, tighten down your memory's timing as low as you can. Go from 9-9-9 to 8-8-8, to 7-7-7. As soon as the BIOS safe mode kicks in upon boot, you crossed the line and have to go back to the previous timings.
Closing
Well.. this became quite the essay about this board, but I enjoyed writing this up and share this with you. Hopefully there's some useful information in there to have other N790 owners get the best out of their boards. Enjoy!
Settings and other
Multi: 8x
FSB: 1600MHz
DDR: 1600MHz, 7-7-7-21-T1
CPU Volts: 1.3750 configured = 1.3250 effective
DDR Volts: 1.8V
FSB Volts: 1.2V
NB Volts: 1.3V
SB Volts: 1.5V
These settings result in a 38degrees idle, and 56degrees load for the Q6600. NOTE: The C1E Enhanced Halt option of the CPU can still be enabled with this board. It lowers your idle temps and power consumption significantly and it doesn't make the overclock any less stable unlike on many other boards out there.
This is my first post on this very nice forum so please bear with me
So hello to everyone and let's hope this topic will be of use to some of you. To start off, I have a love for overclocking my gear and like a half a year ago, I got a Gygabyte X38 DS5 board. It appeared to be a pain in the ass to overclock, it would never be really stable. In the end, I changed everything back to stock and it still remained sort of unstable. And trust me - it was the board. Cooling wasn't an issue. A week ago I searched for a nice replacement board, and reading around, I was quite impressed with the XFX N790i board. I also got aware of the "data corruption" troubles this board would have. Well, two days ago I picked up my prize and began to play with it. Through this topic I would like to share my results and thoughts on overclocking this board. I will also make a note on the data corruption. So here goes...!
The Rig
The current rig now consists of the following:
- Intel Quad Core Q6600 G0 stepping cooled by Thermalright Ultra 120
- XFX nForce 790i ULTRA
- ASUS EN8800GTX
- 2GB OCZ DDR3-2000 SLI Ready kit
- Silverstone 850 Watts PSU
- Promise FastTrack S150 SX4 Raid Controller
Overclocking, the CPU and Mobo
It is a great board, but as with any great board, you'll need to find out how to treat it. To start off with the CPU, I know mine was able to deal with a 1800ish FSB maximum. I left all the board's settings on auto, except for the EPP2.0 setting that would unlock the FSB controls. I felt bold, and set the FSB to 1600 and the multi to 7 without configuring anything else.
As the board rebooted, it hicked up a few times, apparently not wanting to complete the POST. As it appeared, the board has a nifty feature that attempts your new settings, and if the board thinks it ain't going to work it tries 2 more times. On the 3rd reboot time, the board enters safe-mode, defaulting CPU and memory speeds. It still retains all your settings though. In my experience, it works better than ASUS's CPR, which is a similar feature.
So here I was. Why wouldn't the board just complete the POST at a 1600FSB? I went back into the BIOS, looked at the auto adjusted voltages and saw most being green. Meaning, the board had upped the majority of the voltages. The CPU voltage to a whopping 1.4v, as well as the FSB voltage and the NB voltage. Well, then I decided to lower the FSB to 1333MHz and saved. Well..! Now the board didn't hickup and I booted straight into windows.
The first benches were not too impressing. Especially the memory bandwith benches. Still, I was puzzles why the board wouldn't do a 1600 FSB. Then it got me thinking. On previous nForce boards I learnt that upping the northbridge voltage anywhere over 1.35V had an adverse impact on overclockability. Don't ask me why, it's what I experienced.
In my quest to find the highest attainable FSB for my Q6600 in combination with this board, I went back to the BIOS and put ALL foltages to stock levels, taking them off of "Auto". The CPU Vcore voltage however, I set to 1.3V as in my experience that is a nice start to have the CPU run at a 1600FSB. After saving the settings, the board continued its post without a hitch, ending up in my Windows XP, seemingly rock-solid. After running some benches and using Prime95 for half an hour just to check short-term stability, I was getting a smile on my face. This brings me to the first guideline for this board:
Do not let the N790 manage voltages. Set ALL voltages to their stock defaults manually. 1.2V for the FSB Voltage, 1.3V for the NB Voltage, 1.5V for the SB. In case of my memory, it was 1.8V stock.
As I have discovered, I never even had to increase the NB voltage or the FSB voltage for that matter. The only voltage you will be modifying is the CPU Vcore voltage. And so I went on with my quest. Eventually, I could get an FSB of 1750MHz on this Q6600, running at around 3ish GHz. However, the Vcore was set to a whopping 1.475V.
While the system was stable, and temperatures not too shocking (62-65 degrees under load), I noticed I was getting into the area where the needed Vcore jumps became to high in relation to the FSB jumps.
Overclocking the Memory
Now it was time to play with the memory. Since this memory was rated 2000MHz @ 1.8V, I knew that the memory would have plenty headroom. I still had the FSB at 1750MHz. And so I set the memory clock to 2000MHz. Well, the rig booted, but then halfway loading Windows, I got a BSoD. No biggy. I restarted the computer. And again, this BSoD. Hmm, now it was time to set everything back to stock, just to be sure. After a reboot, AGAIN this BSoD. So I started to think.. "This must be the data corruption they've been talking about". And so it was. I had to restore a disk image to get started again.
I got back into the BIOS and looked at frequencies. It pretty much looked not right. The memory speed wasn't exactly a whole 2000MHz, but it was a 'broken' number. Obviously there was no suitable FSB:Memory ratio to make the memory speed a clean whole number. I prefer clean, whole numbers. Then you can tell by the numbers that everything is synched properly. Then, I set the memory to the same 1750MHz, and didn't experience any more data corruption. However, after running benches I was unimpressed. Now here a finding regarding memory on this board:
Always use the Unlinked FSB/Memory clock mode! And, always adjust either clocks in such way that they form a solid granularity, where you end up with whole numbers, or nice broken numbers (like 1333.3). Avoid using the exotic division ratios.
Although data corruption is not fun, I really would not attribute this to NVidia or the N790 chipset specifically. And let me tell you why. When you overclock, there is the risk that anywhere in your system, bits may flip. Read instructions may become write instructions. Addresses may point to wrong locations. As you know, Windows XP writes to disk during bootup and on shut-down. If any number of bits change value and get written back to disk, you're screwed. Most of the time you will not even notice datacorruption while overclocking. But it happens, trust me. I have had many boards in the past that exhibited data corruption to the point where the OS would not boot any more. Today's hardware is very delicate. Not increasing Vcore high enough may cause corruption. Unsynchronized clocks may cause timing problems and cause corruption. Too high voltage on components also causes data corruption. So if you wish to overclock this board, or any other board:
Before you begin any overclocking, make a backup image of your OS drive always! Use software like Norton Ghost for this. Then you can always revert back to a working OS in case you ended up with a harmful combination of settings. Once you are done overclocking and found your golden sweetspot, then you can restore your harddrive image. Even if your OS still boots and no apparent corruption is there, do it still, as there definately may be corruption that you won't notice untill later down the road.
Tuning together the Components
As known with the nForce chipset, it begins to insert latency when its FSB is higher than 1600MHz. This, and the fact that I wanted temperature headroom on my CPU (by doing with lower Vcore), I decided to make the 1600MHz my FSB reference. Now it was time to up the multiplier again, and see how fast I could get the CPU. 3.2GHz (8x) was rock solid, at an initial 1.3750v Vcore. The actual Vcore is lower though. The board has a droop of about 0.050V. Load temperatures got up to around 55 degrees maximum. So I gave the 9x multi a whirl, having the CPU run at 3.6GHz. I could get it stable, but it needed a good 1.4750V Vcore which was like 1.4250 effective. Although temperatures weren't extreme with their up to 64degrees, I felt there was too few headrom left as room temperature can increase. And as with determining the max FSB for the CPU, Vcore steps became too big in comparisson to MHz jumps. I decided to go with a rock-solid 3.2GHz @ 1.3250 effective Vcore.
Now it was time to adjust the memory. Since there was a nice divisor that allowed a nice whole number of 2000MHz in conjunction with the FSB speed of 1600Mhz, I tried this out. After running benches, I wasn't too pleased with read performance of barly 8GB/sec. I'm sure that the memory speed between the GPU and Memory would be more than fine. But between the CPU and memory it was disappointing. So, time to now set the memory frequency to a 1600MHz also. At the same time, this allowed me to tighten the timings on the memory as well. From 9-9-9-28-2T all the way down to a very nice 7-7-7-21-1T! Going back to Windows and running the EVEREST memory bench, I now saw this very nice, whopping 10.7GB/Sec on reads, 8GB/Sec on writes and copies. That made me smile big-time. Another conclusion I drew from this:
Try to keep your memory speed the same as your FSB speed (actually twice as fast, as DDR is base x2, and FSB is base x4). This requires the least synchronization efforts by the northbridge. Secondly, tighten down your memory's timing as low as you can. Go from 9-9-9 to 8-8-8, to 7-7-7. As soon as the BIOS safe mode kicks in upon boot, you crossed the line and have to go back to the previous timings.
Closing
Well.. this became quite the essay about this board, but I enjoyed writing this up and share this with you. Hopefully there's some useful information in there to have other N790 owners get the best out of their boards. Enjoy!
Settings and other
Multi: 8x
FSB: 1600MHz
DDR: 1600MHz, 7-7-7-21-T1
CPU Volts: 1.3750 configured = 1.3250 effective
DDR Volts: 1.8V
FSB Volts: 1.2V
NB Volts: 1.3V
SB Volts: 1.5V
These settings result in a 38degrees idle, and 56degrees load for the Q6600. NOTE: The C1E Enhanced Halt option of the CPU can still be enabled with this board. It lowers your idle temps and power consumption significantly and it doesn't make the overclock any less stable unlike on many other boards out there.