AMD Phenom II Quad.

UglyDuckling

Senior member
May 6, 2015
390
35
61
Ok so i was on Windows 10 x64, and i ran into problems with both Battlefield 3 and 4, both stuttered uncontrollably, which never happened previously on Win 7, so i am now back on Win 7.

I am also experimenting with overclocks, see my chip was at 4.0ghz with Northbridge at 2000 and the HT link at 2000, in Cinebench i would score around 370CB which is good for this chip.

So i decided to change it up, bring the CPU clock down to 3.9ghz, the NB up at 2600mhz and the HT link at 2400mhz, i now score 388 CB which is as fast as a 6 core Phenom II at 3ghz.

Anyone know anything more in depth about how these chips work, and what gains the largest performance gains?
 
Dec 30, 2004
12,553
2
76
that CPU-NB at 2600mhz is perfect for 4ghz, so even if your cores only hit 3.9ghz you're still fine. that really speeds the chip up as you're seeing in the scores. In games and branch heavy code particularly you can see 10 up to 15% improvement. on average about 12-13% You probably able to hit 4ghz honestly on the cores if you can hit 3.9. Windows 10 might have some scheduler issues or something
 

UglyDuckling

Senior member
May 6, 2015
390
35
61
that CPU-NB at 2600mhz is perfect for 4ghz, so even if your cores only hit 3.9ghz you're still fine. that really speeds the chip up as you're seeing in the scores. In games and branch heavy code particularly you can see 10 up to 15% improvement. on average about 12-13% You probably able to hit 4ghz honestly on the cores if you can hit 3.9. Windows 10 might have some scheduler issues or something
So with AMD chips the CPU core clock is really not the be all end all of overall performance? Thanks for answering BTW :)
 
Dec 30, 2004
12,553
2
76
So with AMD chips the CPU core clock is really not the be all end all of overall performance? Thanks for answering BTW :)

you can google more for the details it's been 2 years since I found it but someone with better computer engineering experience than I was able to determine based on architecture details that ~2.2ghz CPU-NB was what was needed to keep the Phenom2 cores fed in the 965 at 3.4ghz, and scaling that to 4ghz meant you needed the CPU-NB to be right at 2.6ghz for the CPU to never stall on the L3.

I had an X3 720-BE that I unlocked to an X4 and overclocked to 3.5ghz/2.6ghz CPU-NB, but I wanted 4ghz so I sold that and upgraded to a 965 which I oc'd to 4ghz/2.6ghz CPU-NB. In both cases I had to give an extra 0.2v on the CPU-NB, but considering we were talking 1.2->1.4 and 1.1->1.3v, I wasn't the least bit worried.

I also discovered that, at idle, having overclocked via the bus, and not just the multiplier, was superior as far as system responsiveness goes. I would still have that system now if Chrome hadn't demolished my RAM. Well, that, and I think when I switched from NVidia to AMD GPU their driver set aside 2GB of system RAM for no reason whatsoever-- I began encountering issues at ~6GB RAM with my swap file turned off, whereas before I could bump right up against 7.8GB RAM used without problem...not sure what caused that, but I gave up trying to pull more hair out and just upgraded my sig rig below.

On the FX series, however, the L3 cache isn't a bottleneck, suggesting improvements in the ... branch prediction ... I think ... overclocking it doesn't do hardly anything (3-4%) excepting WinRAR archiving where it makes a 10-15% difference like we saw across the board in the Phenom 2's.

I guess I'd need to see benchmarks of memory bandwidth scaling on a highly overclocked FX, and then add in L3 cache overclocking, to be able to say whether it's the branch predictor or something else that got better. I think I'm getting rusty, too, I believe I'm leaving something out.

Anyways, to answer your question, yeah. You should still prioritize the CPU clock, but the CPU-NB should be a very close second. You can see the score and performance difference yourself running WinRAR's benchmark. This final touch to the Phenom2 overclocking was something many review sites left out and brought the Phenom2 just a hair shy of Penryn clock-for-clock performance parity-- and, of course, being able to hit 4ghz on $100 Gigabyte AMD motherboards vs $200 Intel-cpu motherboards was significant, too. It was the icing on the cake that made me really love the Phenom 2. I really wish I would have kept it-- at 4/2.6 all I needed was more RAM, which I have now, but to get that I also stumbled on an FX-8310 for $80 AFTER shipping and tax from TigerDirect. I ended up selling my Ph2-x4 965 for $65 on ebay and my 8GB RAM and Gigabyte mobo for $80. I got a CPU/Mobo bundle for $140 from microcenter (FX-6300), and immediately purchased the FX-8310 when I found that $80 deal and ebay'd the FX6300 for $95. LOL ():)():):D:D but I still wish I could have kept the Phenom2 :( :( :(
 
Last edited:
Dec 30, 2004
12,553
2
76
for reference, my 965 needed 1.4425v on the CPU and 1.3v on the CPU-NB for 4/2.6ghz. That was a C3 stepping chip. The x3-720 was a C2 stepping and needed 1.4725v/1.4v for 3.5/2.6ghz. As far as temperatures went, those two were basically identical under load.

the x3-720 -> x4 unlock and overclock was probably one of the the coolest and best bang for bucks at the time, everyone was talking about how great highly clocked dual cores were, meanwhile I was still hitting 60fps in all the games, and had the bandwidth for multitasking, faster video encoding, and 8 years later it was still relevant, 3-4 years after people started having problems with dual core systems.
 
Last edited:

sm625

Diamond Member
May 6, 2011
8,172
137
106
I am also experimenting with overclocks, see my chip was at 4.0ghz with Northbridge at 2000 and the HT link at 2000, in Cinebench i would score around 370CB which is good for this chip.

So i decided to change it up, bring the CPU clock down to 3.9ghz, the NB up at 2600mhz and the HT link at 2400mhz, i now score 388 CB which is as fast as a 6 core Phenom II at 3ghz.

Unless you repeated these tests several times I would chalk it up to measurement uncertainty. Hopefully that is what it is because...well... otherwise it would be very bad.
 

LTC8K6

Lifer
Mar 10, 2004
28,520
1,576
126
Ok so i was on Windows 10 x64, and i ran into problems with both Battlefield 3 and 4, both stuttered uncontrollably, which never happened previously on Win 7, so i am now back on Win 7.

I am also experimenting with overclocks, see my chip was at 4.0ghz with Northbridge at 2000 and the HT link at 2000, in Cinebench i would score around 370CB which is good for this chip.

So i decided to change it up, bring the CPU clock down to 3.9ghz, the NB up at 2600mhz and the HT link at 2400mhz, i now score 388 CB which is as fast as a 6 core Phenom II at 3ghz.

Anyone know anything more in depth about how these chips work, and what gains the largest performance gains?

Win10 should be as fast or faster than Win7.

Probably video drivers.
 
Dec 30, 2004
12,553
2
76
Unless you repeated these tests several times I would chalk it up to measurement uncertainty. Hopefully that is what it is because...well... otherwise it would be very bad.

no, his scores are in line with what mine were, as are the CPU-NB overclocking improvements (though a tad on the low side). Cinebench is less inaccurate / is more consistent in scores since 10 / 'the motorcycle one' where it split horizontally instead of into small little squares for each render.

also, the HT link speed doesn't do anything at all. You actually get better performance with it clocked lower....
 
Last edited:

UglyDuckling

Senior member
May 6, 2015
390
35
61
no, his scores are in line with what mine were, as are the CPU-NB overclocking improvements (though a tad on the low side). Cinebench is less inaccurate / is more consistent in scores since 10 / 'the motorcycle one' where it split horizontally instead of into small little squares for each render.

also, the HT link speed doesn't do anything at all. You actually get better performance with it clocked lower....
I will lower the HT to stock and report back on my CB score.
 

UglyDuckling

Senior member
May 6, 2015
390
35
61
My score lowered with the HT link at stock but by 3-4 points, i ran it twice, it scored 385CB on the first pass, then 384 on the second, so within margin of error.

KU7NRK0.jpg
 

SlowSpyder

Lifer
Jan 12, 2005
17,305
1,002
126
A lot of people only adjusted the core multiplier when overclocking the PhII, they left a lot of performance on the table. I ran mine at 2.6GHz/4.03GHz.
 

DrMrLordX

Lifer
Apr 27, 2000
22,886
12,943
136
I observed performance improvements from NB overclocking when running L3-less Stars chips such as Propus. It helps the memory subsystem even in the absence of L3 cache.
 

UglyDuckling

Senior member
May 6, 2015
390
35
61
You'd think Win10 causing stuttering in games would be widely discussed, though.

Is it?

Do you think every consumer has:

AMD Phenom II x4 B55 4.0ghz
4GB 1600mhz ram
1GB HD 7770
MSI 790FX-GD70

?????????????

Exactly, if it's not working for me, then it's not working for me, BTW my issue is fixed, works fine under Win 7.