overclocking help

collisster

collisster

collisster

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as in title, I have read the stickies and they didn't help, what I'm reading now online is though. I have some questions tho.
why do you have to lower the HTT bus once you increase the base frequency?
I'm confused about ram timings and I'm really not bothered about Ocing my ram can I just lock it and not mess with it?

* 1. Lock the clock of all other devices but the CPU with their default clock rates, if your motherboard provides this option.
* 2. Change the CPU base clock configuration from “auto” to “manual”, if necessary.
* 3. Increase the CPU base clock step by step checking if your system is still running stable.
* 4. Change the HyperTransport bus clock multiplier from x5 to x4 once you surpassed the 220 MHz clock rate, if your motherboard provides this option and you use a CPU with 1,000 MHz HyperTransport bus (a.k.a. “2,000 MHz” or “4 GB/s”).
* 5. Change the HyperTransport bus clock multiplier from x4 to x3 once you surpassed the 225 MHz clock rate, if your motherboard provides this option and you use a CPU with 800 MHz HyperTransport bus (a.k.a. “1,600 MHz” or “3.2 GB/s”).
* 6. Change the HyperTransport bus clock multiplier from x4 to x3 once you surpassed the 275 MHz clock rate (if you are that lucky) if your motherboard provides this option and you use a CPU with 1,000 MHz HyperTransport bus (a.k.a. “2,000 MHz” or “4 GB/s”).
* 7. Change the HyperTransport bus clock multiplier from x3 to x2 once you surpassed the 300 MHz clock rate (if you are that lucky), if your motherboard provides this option and you use a CPU with 800 MHz HyperTransport bus (a.k.a. “1,600 MHz” or “3.2 GB/s”). .
Click to expand...
 
Usually it's just the HTT/LDT multiplier you have to change, not the actual speed.

On my board for instance, the CPU frequency/bus speed at default is 200MHz. This dictates both the CPU speed and the HTT speed i.e.

200 x 10 = 2.0GHz CPU & 200 x 5 = 1,000MHz HTT speed

If I were to increase the bus speed to say 220MHZ, the net result would be:

220 x 10 = 2.2Ghz & 220 x 5 - 1,100 MHz

It's best to have the HTT running as close to 1,000 MHz as possible because if it's set higher, it can lead to instability. That's why in the above overclock, you would usually change the HTT multiplier from the 5 to 4 to give you 880MHz HTT.

There's no real world performance difference if you have the HTT speed at less than 1,000MHz within reason (600 - 1000MHz I would say). The 'real' HTT speed however is 2,000MHz because it's double data rate (DDR).
 
I'm still getting to grips with RAM timings myself but as far as dividers go, it's all about ratios. If you run your RAM on a 166 divider (aka 5/6 ratio) for instance, for every 6MHZ of CPU speed, your RAM only gets 5 MHZ.

For example, 200MHz on a 166 divider will give you the following: 200 divided by 6 & multiplied by 5 = 166 MHz. A simplified way of doing this is 200 x 0.66

Whereas a 133 divider will give you: 200 divided by 6 & multiplied by 4 = 133 MHz. Hope this helps, if not, try googling 'ram dividers' for something more indepth.

Dividers are basically used so that you can overclock the CPU without making the RAM faster than it's rated to. In my case for example, I'm running 250MHz x 10 = 2.5GHZ but as my RAM is on a 166 divider, it's running @ 208MHz.
 
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ah right, I sorta got that, but how to you get
divided by 6 & multiplied by 5
Click to expand...
from 166

edit I read thru again but still a little confused.
how do you overclock your ram then ??
info. my cpu is a amd 3700+ 939
my ram is geil value ram 1gb
my mobo is asua a8n sli premium

has anyone else got these components and overclocked them?
 
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Most AMD based CPUs have a stock FSB (or whatever you wanna call it) of 200MHz and if you think about it, this can be broken down as 33.3MHz multiplied by 6. So therefore, 166MHz is 5/6 of 200MHz, hence the dividing by 6 and multiplying by 5.

Overclocking your RAM just means that it is running faster than it was intended to. DDR400 (PC3200) for instance is rated to run at 200MHz (400MHz effective because it's double data). In my case, the RAM is only running 8MHz quicker than it should do but I don't really care about that, as the CPU is 500MHz quicker :)
 
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Your CPU will run at default with an 11* multiplier and a 200mhz FSB speed, and a 1:1 divider
which is also your (memory speed*your divider),
so normally on a a 1:1 divider your FSB will be 200mhz, and your memory will be at 200*1 =200 mhz ( :p )

Your value ram may not do much above 200mhz, to find out, firstly set your HT multiplier to 3*, it wont make any difference setting it lower anyway, and will just hinder you when you try to overclock the FSB, then set the CPU multiplier to lower than default, say 8*, this will mean your CPU speed also wont affect your testing as it will always be below default (therefore never possibly unstable).

Then increase your FSB (and thus also your memory speed) in small increments, such as 4-5mhz at a time, and try booting to windows and run a stability test like prime95 (available HERE ) if your computer is unstable getting into windows or fails the stability test then you have reached your memories maximum speed.

You should note this max speed down, with value ram it is quite random, you could get memory that wont budge much over 200mhz at all, or you could get some that will do 230mhz plus.

Once you have found out your maximum memory speed, you can start trying to find the maximum stable overclock for your system, firstly set the CPU multiplier back to default 11*, but leave the HT at 3*, then start increasing your FSB by 5mhz and testing in windows, this is a slow process but ensures you wont go wrong and hurt your PC, you may well find your computer is completely stable as you increase your FSB (and also your memory speed remember) upto the maximum stable memory speed you found earlier, if this happens (and it probably will as 3700's are very good overclockers in general) then you need to start using a multiplier.

Multipliers make overclocking a little more complex, but its all still straightforward if you take your time about it.
By changing your multiplier from 1:1 (or 200mhz setting as some motherboards call it) to a divider where memory is less than CPU, such as 166mhz you can get round this potential maximum memory speed problem.

The key bonus here is now the memory that is rated at 200mhz is only running at 166mhz initially. So you can start pushing up the FSB a lot higher than you did before, best bet to save some time is to set your FSB to wherever you got stuck whilst using a 1:1 ratio, for example you may have got stuck at 220mhz FSb, so pick straight up from here, and keep going.

If you reach your memory speed maximum again, lower the divider even more and keep pushing until you get to a point where the CPU speed is causing the stability test to fail (or windows crashes when you boot :p ) and back off a few mhz. Hopefully on a 3700 you should reach 2.8ghz if you have a better than the default AMD cooler :)

I dont know if thats useful, you may have gleaned all that info from the myriad other overclocking threads on here, but im feeling like typing a lot at the moment :)
 
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collisster said:
ah right, I sorta got that, but how to you get from 166

edit I read thru again but still a little confused.
how do you overclock your ram then ??
info. my cpu is a amd 3700+ 939
my ram is geil value ram 1gb
my mobo is asua a8n sli premium

has anyone else got these components and overclocked them?
Click to expand...

Hi Collisster. I've got the same CPU and motherboard as you have. (I think it's the premium any way). I'll try to knock out this quick guide before my boss comes back:

I've got mine running at 2.75 gig.

I set the CPU to manual, and set the FSB of it from 200 to 250.
Set the Multiplier to 11.

Go to the memory config screen and set the RAM from 400 to 333 speeds.
Also check the PCI-Express is still set to 100, and then lock the PCI speed to 33.

Boot it up. If you're lucky then you'll see the RAM speeds show at boot as DDR 333 (which is 166Mhz).

Let windows boot and have a check of the speeds using CPU-z.

You should see you're at 2750Mhz, , FSB = 250 using RAM at 196Mhz. Check the memory tab and you'll show to be using CPU/13 to get the RAM speed.

I hope this helps.

If it's not stable then go back into the bios and lower the FSB from 250 down a bit.

Here is a couple of pictures with the FSB running at 260 but it wasn't stable:

cpu-z1a.jpg


cpu-z1b.jpg
 
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thanks, I'll put that into the bios and see what happen, but before I do should I get a new cooler? also what speed is the ram runnning at (after Oc)?

also my core speed keeps changing its at 2.4ghz I think it is cuz of the Ai ***/booster I enabled cuz the core should be at 2.2
 
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I've done it....., like 10 mins ago heres a screenie of the speeds how should I check if it is stable or not? thanks, what are good temps also?
overclocked.png
 
I just played 2 hours of BF2 with no BSODS or whatever is considered and error, the temps on the core never went past 55 degrees, is this clock stable ?
 
That may be why u get errors, due to lack of juice goin to the CPU.

Things like Prime95 and Orthos really show up a CPU if it is running a bit high with lack of power.

Wouldnt mind a second opinion to confirm this, as not sure about the voltages for AMD 64 CPUs, went from AMD 3000 to C2D.
 
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