Reference Clock Limit with Phenom?

[devguy]

Hey guys. I've had this Phenom x3 for quite some time, but lately I've had some spare time and I've been trying to push it harder. I can get this thing to near 3.2Ghz with 1.5V and be stable, but I can't go any further. For the life of me, I cannot get this thing to post past a reference clock of 276mhz! I've tried knocking down all multipliers, upping chipset voltage to 1.5V, even increasing HTT/HTR voltage (wtf good is HTR voltage increasing?). Looking around online, it seems that most people cannot seem to get above the 270mhz on the bus, no matter what AM2+ board or Phenom.

I think this may actually have something to do with Phenom because I know this board is capable of more. When I had my K8 4000+ in here, I had that thing up at ~310mhz with 1.3V on the chipset. With Phenom, I'm limited? Anyone else here come across this? Also, those of you getting the Phenom II, I'm curious to see if this has the same limit. Could those of you who aren't pansies that just up the CPU multiplier on their fancy-schmancy black editions nutkick: J/K of course), see if you come up with some similar behavior?

Oh, and BTW, I'd like to show off some of the fruit of my labor so far. Check out these RAM timings at 2.1V! Yeah, they look like the timings of my old DDR1 RAM! I've found a huge reason why I couldn't get better RAM overclocks had to do with not pouring additional voltage into the NB Memory Controller as opposed to the VDIMM. I almost had FOUR PC26400 modules stable at PC28500-6-6-6-18-2T with an extra .125V on the Northbridge.

 

[cdawall]

i got 280mhz out of my phenom 9500 and K9A2 platinum i cant get over 240 (so far) on my 7750 kuma chip but its a bad chip so back off to newegg for it

 

[Kei]

On my Phenom 9850BE I was able to get a max HT Bus speed of 266Mhz but can't go any higher than that. However I can hold that 266Mhz bus speed all the way up to a multiplier of 11.5x which is sweet for such a high bus speed on an AMD quad core.

http://forums.techpowerup.com/showpost.php?p=872409&postcount=1641

With my old Phenom 9500 I was able to go to a max HT Bus speed of 283Mhz and ran 275Mhz as my daily setting.

With my 4800+ I was able to go up to over 300Mhz stopping my testing at around 311Mhz or so but that was on a 790X board not the 790FX board I use now (still SB600 not the new SB750 which may fare better).

The highest bus speed I've seen so far around here on a Phenom is an insane 293Mhz done by Viscarious

http://forums.techpowerup.com/showpost.php?p=874222&postcount=1711

I've not tried to find the highest bus speed again since getting the latest bios a month or two ago, but I imagine I could go a little higher considering every other parameter is significantly better for me especially voltage (I run daily 2.6Ghz @ 1.152v stress tested 100% stable stock 2.5Ghz speed takes only 1.072v) which was already really good considering I could boot and run for a while at 3.0Ghz @ 1.200v w/o BSOD unless lots of stress was introduced. I've not retested to see if 3Ghz at 1.200v would be 100% stable now with the different bios but I doubt it considering 2.9Ghz took a little bit more but don't remember what bios that was so maybe...

Kei

 

[devguy]

Yeah Kei, I have my Phenom x3 with the same reference clock and multiplier as your 9850. I have noticed another sort of anomaly as well, though. The RAM speed divider seems to have a profound effect on the max reference clock when everything else remains the same. For example, with a RAM divider where the default is 533mhz (2.66x) I can reach my max of 276mhz. On 800mhz (4.0x), I can run at the 266 I am now, but that makes my RAM run at 1066mhz, which I can't get them to do stably for the life of me. However, when I use the 667mhz speed (3.33x), I can't get past 156mhz. I'll try the lowest RAM divider later just to see what happens.

I wonder if this has something to do with a lot of Phenom owners who cannot seem to raise the reference clock more than 10-20mhz? They may be running at a RAM divider which doesn't like the increase in the reference clock. Perhaps if they tried some different dividers, they'd have more luck? It seems to be a Phenom quirk rather than one of my board, though, because with the old K8 in this same board, I had the reference clock over 300mhz, regardless of the RAM divider.

 

[chaotic_uk]

i got 280mhz out of my phenom 9500 and K9A2 platinum i cant get over 240 (so far) on my 7750 kuma chip but its a bad chip so back off to newegg for it

have you killed another kuma chip ?