Overclocking Phenom II 720 BE - Overclock.net

mtl777 · 07-02-09

Hi, I'd like to OC my Phenom 720. I just have a few questions:

1. Comparing a simple increase in CPU base frequency only vs a simple increase in the multiplier only, which one yields better performance?

2. If I OC my CPU, do I need to make any changes to my RAM settings (DRAM frequency, voltage, timings, etc.)?

3. With room temp at 72F, my CPU idle temp is 33C and load temp is 46C after 3 hours of OCCT. Are my temps good enough for a mild OC of up to 3.7 GHz only?

4. There is an option in my BIOS for easy overclocking in which you just select the percentage and it will do the BIOS settings for you. Is this reliable and safe to use? What do you think of this?

That's all for now. Thanks in advance for any help or opinions you could share!

Tator Tot · 07-02-09

1.) No. 3.0ghz (200x15) is the same performance as (223x13.5)

2.) You might need to change your divider if you plan on running DDR3 1600mhz. As Phenom II CPU's are designed for DDR3 1333mhz native. 1600mhz is an Overclock.

3.) Your idle temp may be a little high, but you should be just fine.

4.) 4 such an option doesn't exist and wouldn't be safe. Just bump your voltage to 1.4 and increase the multi.

jimibgood · 07-02-09

Quote:

Originally Posted by Tator Tot

1.) No. 3.0ghz (200x15) is the same performance as (223x13.5)

2.) You might need to change your divider if you plan on running DDR3 1600mhz. As Phenom II CPU's are designed for DDR3 1333mhz native. 1600mhz is an Overclock.

3.) Your idle temp may be a little high, but you should be just fine.

4.) 4 such an option doesn't exist and wouldn't be safe. Just bump your voltage to 1.4 and increase the multi.

???? They are not the same performance. Raising HTT also raises Ram frequency, NB and hypertransport. Higher Hypertransport (bandwith)does not increase performance but higher Northbidge and Ram frequency sure will.

Take your NB and Hypertransport off auto and you will see each increase with higher HTT along with Ram frequency. You have to watch all 3 because if you get too high you will need a voltage increase and if you get real high you will not boot. Keep Hypertransport 1.8- 2.2. There is no need to get real high on this because all you do is raise bandwith. NB Frequency can be run 2400-2800 but at 2600 or higher you will probably need a voltage increase but higher NB frequencies will raise performance. Same with Ram. It is better to lower your frquencies via divider because higher HTT will raise frequency and this may give you more headroom.

Shooter116 · 07-02-09

edit: wrong thread.. lol

Tator Tot · 07-03-09

Quote:

Originally Posted by jimibgood

**clipped for size, but all relevant.**

Unless you are able to pull a High HTT clock out of your build, the little bit that it does increase will limit you to your max CPU clock, and unless you are going for a very RAM intensive rig, the boost in NB clock or RAM speed will not perform as well as the extra 200mhz you get from the CPU.*

*Based on my own testing, my chip (which is a nice one I might add) can pull off a max of 3.2ghz with HT overclocking, (238x13.5) or (267x12). Either way, that is my stable point, no matter what I set my vCore, HT multi, or RAM divider at.

Considering I have 1066mhz sticks running at a default Mem Clock of 800mhz, I know for sure it's not them. Even though I tried dropping the default clock down to 667. (as low as Phenom's will go)

LethalRise750 · 07-03-09

I gained 4-5 GFlops from going from a 2000Mhz NB to 2700Mhz. I also gained a good 10-15% boost in most games from doing it. My Memory Bandwidth went up a good 1000-1100MB/s on Read, Copy and Write.

mtl777 · 07-03-09

Thank you so much for all your suggestions!

I'll play with them and get back with what I find. There's just one thing I'm not sure of...

Quote:

Originally Posted by Tator Tot

2.) You might need to change your divider if you plan on running DDR3 1600mhz. As Phenom II CPU's are designed for DDR3 1333mhz native. 1600mhz is an Overclock.

I don't see a divider option in my BIOS. All I can change is the DRAM frequency. How do I change the divider if I want to run DDR3 1600? Sorry if this question is stupid as this is my first time to OC and I'm new to this.

Tator Tot · 07-03-09

Quote:

Originally Posted by mtl777

I don't see a divider option in my BIOS. All I can change is the DRAM frequency. How do I change the divider if I want to run DDR3 1600? Sorry if this question is stupid as this is my first time to OC and I'm new to this.

You might not be able to, as that is more of a "budget" board, so it's not going to have the options of the more high end boards.

Again, if you can auto set your board to DDR3 1600mhz and post then that's good.

Usually when a board has an option to set your RAM at a certain speed (IE a list to choose from 1066/1333/1600) then it will auto set the divider so you don't really need to worry about it.

Not always the best option. But it should work just fien

Zatarra · 07-04-09

Quote:

Originally Posted by LethalRise750

I gained 4-5 GFlops from going from a 2000Mhz NB to 2700Mhz. I also gained a good 10-15% boost in most games from doing it. My Memory Bandwidth went up a good 1000-1100MB/s on Read, Copy and Write.

LethalRise, Can you please post a screenie of your settings? I just got the same mainboard your using but am trying to oc a phII 920 the old school way (multiplier unlocked). thanks

mtl777 · 07-05-09

Alright, I tried the following OC settings:

OC Mode = CPU, PCI Async (default is Auto)
CPU Frequency = 214 (default is 200)
CPU Freq Multi = 17 (3638 MHz) (default is 14)
CPU Voltage = 1.375 (default is 1.3)
NB Freq Multi = 12 (2568 MHz) (default is 10)
NB Voltage = 1.2 (this is the default)
HT Bus Speed = 2400 (default is Auto)
HT Voltage = Auto
Memory Clock and all memory-related settings = Auto

Result: Instant error in OCCT

So I tried increasing CPU Voltage to 1.4 and NB Voltage to 1.25. It ran OCCT for a minute then BSOD'd with a "MACHINE_CHECK_EXCEPTION 0x0000009C..." error. Then it started doing a memory dump.

I thought I was changing too many things at once so I put back my NB Freq Multi to 10, NB Voltage to 1.2, HT Bus Speed to Auto, and decreased my CPU Frequency to 212. It spontaneously rebooted after 3 minutes of OCCT.

Then I thought my RAM might be the problem so I set the Flexibility Option to Enabled. This improved things and I thought I finally got it, but after 45 minutes of OCCT it gave me the "MACHINE_CHECK_EXCEPTION" error and memory dump again.

Questions:

1. What does the "MACHINE_CHECK_EXCEPTION" error signify -- are my temps too high (cores were at 28C) or is my CPU voltage too low or is my memory unable to handle the OC or what?

2. What are the maximum safe values for the following:
-- Core temp
-- NB Voltage
-- HT Voltage

3. Could it be that some of my BIOS settings aren't correct for overclocking? I'm wondering about the following settings as I'm not sure what they are for:
-- Spread Spectrum = Disabled
-- Boot Fail Guard = Enabled
-- Secure Virtual Machine = Disabled
-- Enhanced Halt State = Disabled
-- L3 Cache Allocation = BSP only
-- ACPI HPET Table = Disabled

Any other BIOS settings that I should make sure to set correctly? Power management settings? Screen saver settings? Any suggestions for an effective overclocking strategy?

This is driving me nuts.

Please help.

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Overclocking Phenom II 720 BE

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