Weird memory overclocking issue

So I have this memory installed in my computer and I've got my HTT overclocked to 250MHz with a multiplier of 4x. I have the voltage setting in the bios set to auto. It ran in Memtest for 8+ hours with no errors and ran through a CPU/RAM instance of OCCT for 9.5 hours, so I'm pretty sure it's stable.

With my multiplier set at 12x, I open up CPUZ and the memory's clock reads 500MHz (CPU clock / 6). That looks right to me. I step the multiplier up to 13x, fiddle with the voltage until I can boot into windows and fire up CPUZ again, only to find that my memory is now running at 464MHz (CPU clock / 7).

Why is my memory doing this? I can't find the setting in my BIOS that mentions this anywhere, but I could be overlooking it. The memory clock frequency is set to DDR2-800, timings of 5-5-5-12-2T, all advanced memory settings set to auto, the DRAM timing control all set to auto, and all the output driver settings set to auto.

Can anyone help me get my memory to run at the same speed as my HTT, I don't understand why it's magically clocking itself down when my CPU speed increases.

EDIT: Sandra is also reporting the same memory clock as CPUZ.

dealmaster said:

So I have this memory installed in my computer and I've got my HTT overclocked to 250MHz with a multiplier of 4x. I have the voltage setting in the bios set to auto. It ran in Memtest for 8+ hours with no errors and ran through a CPU/RAM instance of OCCT for 9.5 hours, so I'm pretty sure it's stable.

With my multiplier set at 12x, I open up CPUZ and the memory's clock reads 500MHz (CPU clock / 6). That looks right to me. I step the multiplier up to 13x, fiddle with the voltage until I can boot into windows and fire up CPUZ again, only to find that my memory is now running at 464MHz (CPU clock / 7).

Why is my memory doing this? I can't find the setting in my BIOS that mentions this anywhere, but I could be overlooking it. The memory clock frequency is set to DDR2-800, timings of 5-5-5-12-2T, all advanced memory settings set to auto, the DRAM timing control all set to auto, and all the output driver settings set to auto.

Can anyone help me get my memory to run at the same speed as my HTT, I don't understand why it's magically clocking itself down when my CPU speed increases.

EDIT: Sandra is also reporting the same memory clock as CPUZ.

Click to expand...

The divider is automatically selected depending on multiplier.
Here's a divider table that I've found very useful,
http://www.xtremesystems.org/forums/showthread.php?t=105798

Stebly said:

The divider is automatically selected depending on multiplier.
Here's a divider table that I've found very useful,
http://www.xtremesystems.org/forums/showthread.php?t=105798

Click to expand...

So if I want to run my CPU at higher speeds I have to sacrifice memory speed?

dealmaster said:

So if I want to run my CPU at higher speeds I have to sacrifice memory speed?

Click to expand...

Well, yes and no. What is important is keeping cpu/ram @1:1.
You can drop your ram to 667 with lower multiple then raise cpu
freq. higher. Just check your ram bandwidth and play with your ram's
timings.
Edit: CPU freq. is the issue, much more important for overall OC.
You don't have to drop your ram below 800 if you run just a slightly
lower multiple. eg.x11. Your formula for 1:1 is cpu/6 at any ram
speed.

Stebly said:

Well, yes and no. What is important is keeping cpu/ram @1:1.
You can drop your ram to 667 with lower multiple then raise cpu
freq. higher. Just check your ram bandwidth and play with your ram's
timings.
Edit: CPU freq. is the issue, much more important for overall OC.

Click to expand...

OK, how can I be sure my memory is running at 1:1 with the cpu?

dealmaster said:

OK, how can I be sure my memory is running at 1:1 with the cpu?

Click to expand...

lol, you beat my slow edit 1:1 is cpu/6 at any ram speed (see cpu-z on memory tab)
That divider table is really helpful.

Stebly said:

lol, you beat my slow edit 1:1 is cpu/6 at any ram speed (see cpu-z on memory tab)
That divider table is really helpful.

Click to expand...

OK that makes sense, so essentially I want to run at the fastest possible HTT speed and CPU multiplier that still gives me a /6 divider for the memory?

So judging from that table:
CPU multipler = 10, DDR2-667 divider=6, and then whatever my max HTT is would work, or any other combination that yields a memory divider of 6?

Also, what would be better, my previous setting of HTT=245, multi=13, 245x13 = 3185 or
say I get the HTT to run at 280 and set the multiplier at 11 or 12. Is it better to have a higher total clock or a higher HTT?

dealmaster said:

OK that makes sense, so essentially I want to run at the fastest possible HTT speed and CPU multiplier that still gives me a /6 divider for the memory?

So judging from that table:
CPU multipler = 10, DDR2-667 divider=6, and then whatever my max HTT is would work, or any other combination that yields a memory divider of 6?

Also, what would be better, my previous setting of HTT=245, multi=13, 245x13 = 3185 or
say I get the HTT to run at 280 and set the multiplier at 11 or 12. Is it better to have a higher total clock or a higher HTT?

Click to expand...

Essentially the highest cpu freq. with total HTlink at or under 1000, probably
htt multi x3 plus lowest cpu multi depending of course on how fast you can OC CPU or Mem.
I'm at DDR2 667 on a 9xmulti, my mem bandwidth in Sisoft is approx. 9,500
BTW, NICE OC on your 5600+, You can't go wrong if your running cpu/6
Ive got my Team Xtreem running at 4-4-4-10-14-2T

Sorry to barge in but I'm kinda experiencing the same problem, I think. I've memtest+86 my ram for 8 hours going through 5 cycles of all tests @ ram frequency of 300Mhz stock timings. So I think it is more or less stable to atleast boot into windows. My processor at stock speeds is 1800Mhz.

Basically, I tried doing this,
CPU:RAM = 1:1
HTT = 300
Multiplier = 6

My processor frequency should be 1800Mhz and RAM frequency should be 300Mhz am I correct? I don't understand why the CPU:RAM ratio would change when changing the multiplier. I just can't boot into windows with this setting

And I heard that people shouldn't use multipliers such as 5.5, 6.5. What's the problem with this?

Rickster said:

Sorry to barge in but I'm kinda experiencing the same problem, I think. I've memtest+86 my ram for 8 hours going through 5 cycles of all tests @ ram frequency of 300Mhz stock timings. So I think it is more or less stable to atleast boot into windows. My processor at stock speeds is 1800Mhz.

Basically, I tried doing this,
CPU:RAM = 1:1
HTT = 300
Multiplier = 6

My processor frequency should be 1800Mhz and RAM frequency should be 300Mhz am I correct? I don't understand why the CPU:RAM ratio would change when changing the multiplier. I just can't boot into windows with this setting

And I heard that people shouldn't use multipliers such as 5.5, 6.5. What's the problem with this?

Click to expand...

The early am2 x2 cpu's (windsors) don't use 1/2 multi's but the Brisbanes
do. If you list your MB, CPU, Ram it'll be easier to understand what's
happening with your system.
I think you're confused on your settings, perhaps go to default settings in bios then see how you're running.
The htt multi has a max of 5x, so you must be talking about the CPU multi.
If your at 300 HTT you can't use any more than 3x multi to remain below 1000 total htt speed.
Anything above 1025-1050 will usually crash the rig or cause a failure to boot into Windows.
Depending on your particular CPU, the multi's are approx. 6x-15x
My am2 board sets the divider according to which cpu multi is used so this also changes the
cpu/ram ratio accordingly. This is also how you can overclock or underclock the ram.
This is known as using a divider.

Oh ok, sorry about that, I'm using:

Opteron 1.8Ghz S939
Abit KN8
G.Skill Dual Channel DDR500 2GB

Even after following that chart you posted, my settings should be right. Says in the charts that if I were to use Multiplier of 6, at HTT 300 and a CPU:RAM divider of 400 i.e. 1:1. I should be getting 600. Which is DDR600 equilavent of RAM frequency of 300Mhz.

Stebly said:

Essentially the highest cpu freq. with total HTlink at or under 1000, probably
htt multi x3 plus lowest cpu multi depending of course on how fast you can OC CPU or Mem.
I'm at DDR2 667 on a 9xmulti, my mem bandwidth in Sisoft is approx. 9,500
BTW, NICE OC on your 5600+, You can't go wrong if your running cpu/6
Ive got my Team Xtreem running at 4-4-4-10-14-2T

Click to expand...

Thanks very much for the divider table as well as your continued advice, I really appreciate it, being an overclocking newbie.

Right now I've got my computer (at home) running OCCT infinitely (testing both CPU and RAM) and it's running at 270MHz (HT multi=3x) with a multi of 12 for a clock of 3.24GHz, which is pretty good. My original goal was to hit 3.4, but that may not be possible. If the HTT is stable at 270MHz then I'll give 280MHz a whirl, that'd put my CPU clock at 3.36 which would be outstanding. I had to run the voltage pretty high (~1.5v+) to get it to boot and run properly, but with my cooler I never see temps any higher than 52C even at full load. I wanted to use the highest multiplier I could that would still keep the memory at 1:1 with the FSB, so 12 was it. I checked in CPUZ and the memory is running at 540MHz, it passed Memtest so now I'm just going to stress it all day and see how it does. Hopefully it holds up!

dealmaster - have you tried tightening your RAM timings?

Stebly - yes sorry for the confusion you are right. I'll go through my settings again to clarify.

HTT = 300
CPU Multiplier = 6x
HyperTransport Bus Multi = 3x
CPU/RAM : DDR200 (equilavent to 1:1), yes no?

Well with these settings I should be getting:
CPU frequency = 300 * 6 = 1800Mhz (which is my stock processor speed i.e. 200 * 9 = 1800Mhz)

HyperTransport Bus = 300*3 = 900 (my abit board is an nForce4 which is meant to run 1000)

So what should my RAM frequency be then? I'm thinking since the RAM divider is 1:1 then HTT which is 300 should give 300Mhz RAM frequency.

Rickster said:

dealmaster - have you tried tightening your RAM timings?

Click to expand...

No I haven't yet. I want to see if it's stable at 5-5-5-12 before I try tightening things up any. If it's stable at 270MHz then I may try dropping the timings a bit to see how the RAM reacts, though I'd rather have a higher HTT than slightly tighter RAM timings.

dealmaster said:

No I haven't yet. I want to see if it's stable at 5-5-5-12 before I try tightening things up any. If it's stable at 270MHz then I may try dropping the timings a bit to see how the RAM reacts, though I'd rather have a higher HTT than slightly tighter RAM timings.

Click to expand...

I once read a test this guy did and it prove d that tighter timings achieve better results in benchmarks.

dealmaster said:

Thanks very much for the divider table as well as your continued advice, I really appreciate it, being an overclocking newbie.

Right now I've got my computer (at home) running OCCT infinitely (testing both CPU and RAM) and it's running at 270MHz (HT multi=3x) with a multi of 12 for a clock of 3.24GHz, which is pretty good. My original goal was to hit 3.4, but that may not be possible. If the HTT is stable at 270MHz then I'll give 280MHz a whirl, that'd put my CPU clock at 3.36 which would be outstanding. I had to run the voltage pretty high (~1.5v+) to get it to boot and run properly, but with my cooler I never see temps any higher than 52C even at full load. I wanted to use the highest multiplier I could that would still keep the memory at 1:1 with the FSB, so 12 was it. I checked in CPUZ and the memory is running at 540MHz, it passed Memtest so now I'm just going to stress it all day and see how it does. Hopefully it holds up!

Click to expand...

Looks like you're doing very well, tweaking can take days,if not weeks.
Personally, this is a very satisfying way to understand the ins and outs
of our equipment and the general level of understanding our limits of
performance. Great Fun!!
edit; 1.5vcore is a little on the high side for air cooling, but others might
disagree. Your temps seem good though. Maybe over time you can drop
your vcore in small increments and find the absolute minimum that
your chip will OC on. Otherwise Good OC!!
I'm at 1.4725vcore and I'm keeping a close eye on it. I was told by an
oldtimer that 1.45vcore was a safer limit for 24/7 (on air) but what the
hey, this 4600 of mine seems to be hanging in there after almost 1 year. hehe

Rickster said:

dealmaster - have you tried tightening your RAM timings?

Stebly - yes sorry for the confusion you are right. I'll go through my settings again to clarify.

HTT = 300
CPU Multiplier = 6x
HyperTransport Bus Multi = 3x
CPU/RAM : DDR200 (equilavent to 1:1), yes no?

Well with these settings I should be getting:
CPU frequency = 300 * 6 = 1800Mhz (which is my stock processor speed i.e. 200 * 9 = 1800Mhz)

HyperTransport Bus = 300*3 = 900 (my abit board is an nForce4 which is meant to run 1000)

So what should my RAM frequency be then? I'm thinking since the RAM divider is 1:1 then HTT which is 300 should give 300Mhz RAM frequency.

Click to expand...

The divider tables are for DDR2 and I must confess that never having OC'd
a 939 or DDR1 system I'm not experienced with your settings.

I'd suggest reading these sticky's
http://www.ocforums.com/showthread.php?t=391768
http://www.ocforums.com/showthread.php?t=364223

I've actually read those thread before. I'm not sure what's wrong. Seems like I can't boot when the HTT is 300 at any multiplier besides for x4 CPU multiplier. I was thinking it was my mobo but then it was kind of strange when I managed to boot at x4 CPU multiplier. At other CPU multipliers, 300HTT won't boot.
I think I'll post a new thread.

Rickster said:

I've actually read those thread before. I'm not sure what's wrong. Seems like I can't boot when the HTT is 300 at any multiplier besides for x4 CPU multiplier. I was thinking it was my mobo but then it was kind of strange when I managed to boot at x4 CPU multiplier. At other CPU multipliers, 300HTT won't boot.
I think I'll post a new thread.

Click to expand...

My M2N-SLI Deluxe wouldn't bootup past 240-250 on it's initial bios. Have you
managed to lower the HTT to 200x5 equaling 1000? That HTT300 just
seems wrong somehow. I'd really like to see you running problem free,
I thought 200 was your base HTT clock.
Your system is acting as though some basic freq. is out of normal value.

Is overclocking AM2's and S939's the same? I think they are.

Have you
managed to lower the HTT to 200x5 equaling 1000?

Click to expand...

Is that 200*5 HTT*HyperTransport bus Multiplier? Or is it HTT*CPU Multiplier?

I thought 200 was your base HTT clock?

Click to expand...

Yes my Opty 165 is 200 (HTT) * 9 CPU Multiplier. Where 9x CPU Multiplier is max. Which means at stock my Opty 165 is 200*9 = 1800Mhz

What I've said before was I ran my RAM at
HTT:300
CPU Multiplier:4X (the lowest the motherboard would allow)
CPU Voltages: 1.35v (stock)
Memory Voltages: 2.6V (stock)
nForce Voltages: 1.5V (stock)
CPU:RAM divider DDR400 (equilavent to 1:1 am I correct?)
HT Bus Multiplier: 3X

Passing memtest at these settings for over 5 cycles on test 1-8 and even 1 test on test 9. More or less it should be stable at such settings.

With these settings:
CPU frequency should be 300*4 = 1200Mhz
RAM frequency should be 300Mhz since CPU:RAM divider is 1:1. (my RAM at stock runs at 250Mhz just FYI)
Iam able to boot into windows with such settings.

So I wanted to try my CPU at stock speeds (1800Mhz) and my RAM running at 300Mhz. So I changed the settings to:
HTT:300
CPU Multiplier:6X
CPU Voltages: 1.35v (stock)
Memory Voltages: 2.6V (stock)
nForce Voltages: 1.5V (stock)
CPU:RAM divider DDR400
HT Bus Multiplier: 3X

Basically I only changed the CPU multiplier from the previous settings. And this is where I can't boot. Shouldn't my CPU frequency be 300*6=1800Mhz. And my RAM frequency be 300Mhz? Which should run fine since I've already tested my RAM at those frequencies. And obviously my CPU should run at stock speeds. This is where I'm getting confused. Is there something wrong with my calculations?

Even running my CPU multiplier at 5X and HTT of 300 which should mean 300*5=1500Mhz it just won't boot into windows. Only CPU multiplier of 4X with HTT of 300 will boot.

I appreciate your help a lot.

EDIT: Infact I just ran AMD Calculator and using HTT:300, CPU Multiplier: 6X and CPU:RAM divider: 1:1. Gives me the figures I'm looking for. Maybe it's something to do with the restriction on the motherboard?