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...Remember that seemingly in computering there is the average of things and then the fliers that defy explanation.
Been out looking for some things that speak to some results have seen around and about lately. Like fluctuating FSB away from what is set in bios by 5MHz. Up front would think this is not a good thing since the CHV board was not supposed to do it or in other words was fixed when the original CHV came out.
From review in our own Forum.
One very important point to mention is that the Crosshair V does not suffer from bus clock fluctuation that plagued the Crosshair IV. After staring at CPUz for five minutes under load, I saw literally 0.0MHz bus speed deviation. HT freq deviated max 0.3MHz and CPU-NB freq deviated max 0.2MHz. I’d call that a vast improvement over the 890FX fluctuations of the past. Those fluctuations didn’t much affect most people other than to exist. However, those that pushed the Crosshair IV under extreme cooling at the bleeding edge of stability were hampered by their system crashing due to too much bus fluctuation.
I used DFI AM2+ motherboards while working for them and the first board I bought after DFI went non-DIY was an Asus CHV non-Z mobo the first release. So my first experience with Asus was a board that supposedly fixed the fluctuating HT Freq.
NO I do not see my CHV-Z board with a fluctuating HT Ref Freq. I set 205FSB...I get 205 FSB with that 0.07 add that Asus has had for years. I am pretty close to believing that boards that have a FSB that jumps around has a problem. I get that way more as I do not see my CHV-Z and non-Z that do not do it with my FX-8350s.
Alright moving on. Been working with a user in our forums and seeing things that on the surface seem not to add up exactly. SO I went back into "let's go see" mode. Came across some things that while we may have spoken of or about some of these before it might be time to say something again. REmember the fliers.
Our own Johan45:
To run 2400MHz ram you'll need the CPU_NB at 2400+. It's a lot easier to OC the CPU with a ram speed around the 2000 MHz mark or lower. AMD FX processors don't benefit a whole lot from high speed ram and still prefer lower speeds with tight timings. Having high speed ram is just harder on the IMC.
Now Johan may have had to change his stance and go thru more ram and cpus after joining the benchmarking team where all previous bets are off. RGone...
We are not the only ones seeing a difference in FX-8cores that are now in use since early 2014. As seen around forums on the net. What about the FX-8350s pre FX9370 or FX-9590? The 8350's no longer seem to have superior or golden chips among their number. The great chips have all been binned into FX-9370s and FX-9590's. FX-8350s now produced seem seldom to reach 5.0 GHZ. REmember the fliers.
Now how many times have we begun to see this?
Give the 8320 a try, its got 8 threads and most will get you to 4.7?
Not so true any longer it begins to appear. The current 8320 production usually tops out at about 4.5 to 4.6 GHZ. Have an FX-9590. I can not get stability even with 1.60 volts. It has an unusually high VID of 1.488 volts at 4.7 GHZ stock frequency. It will run games but Prime '95 locks up after running a few seconds. I could try 1.65 volts but h*ll I would never run it 24 7 at such a high voltage so I am settling for 4.85 GHZ at 1.58 volts. So NoT even all FX9590's give a stability at reasonable voltage at 5.0 GHZ and above. Humh. Heard similar more and more as FX-9590s begin to come around OCF more.
Oh the freeken ram thing again as mentioned already by Johan above.
I run 16gb of 2400 trident 4x4 dimms, I can get 2 sticks, 8gb stable at 2133 or a little higher, but for 100% stable it's back to 1866 for all sticks running totaling 16gb. No matter core or cpu-nb volts, just stressed the IMC too far. Using initial batch FX-8350.
Ram speed > 1866, 4 dimms, 8-9-9-24 Ram 1.65v & 1.275V CPU_nb
Those were pretty good sticks!!!
Ram speed > 2133, 2 dimms, 8-9-9-27 Ram 1.7v & 1.3V CPU_nb
Ram speed > 2400, 2 dimms, 9-10-(9 or 10)-27 Ram 1.7V & 1.3V CPU_nb
The above may be a general "tale of the tape"about ram speed and amount of ram and elevated CPU_NB voltage as experienced by others.
In bringing the above into focus it seems trending that Pre-release of the FX-9xxx cpus the FX-8xxx cpus tended to overclock higher but with more voltage it seems and that now more often we see FX-8xxx cpus that will not run the bigger Cpu MHz. Dang roll of the dice when buying cpu silicon
As regards what I generally saw it appears one has to have a 'golden' IMC to run fast ram speeds with more than two sticks of ram. Still seems to be a consensus that AMD cpus respond more readily to tighter timings than faster ram. This is nothing that has not seemed apparent for years and more so if you look for 24/7 stability at elevated cpu MHz.
As time has gone on I try and ensure that this long sticky is still relevant and update as time goes on. I endeavored to cull down hours of reading into the real meat of the situation in posting this.
RGone...ster.
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