720BE Unlocked

Hi good day to all!

I'm new to overclocking but already set my 720be 4th core unlocked and I just raised the multiplier 200x18 for 3.6
I already ran it for 12hours utilizing prime95 without errors
Ram was set at 1600mhz at 9-9-9-32
Did not set any particular voltages for ram, nb, cpu

System specs:
Air cooling - Megahalems Megashadow Push/Pull Scythe
Temps at 3.6Ghz Idle: 29C Max: 40C

ASUS M4A785TD-V EVO (updated to latest bios 0512ver)
4x2GB G.Skill rated at 2000mhz
IGP
2x640GB WD Caviar Black (Raid 0)
HX620 Corsair

Windows 7 Ultimate 64bit

BTW room temp is at 13C

Here's my CPUz: http://valid.canardpc.com/show_oc.php?id=932850

The problem was when I have set the rams at 1600mhz with tighter timings 8-8-8-21. I failed prime95 after 5min.

Do I have to overclock my cpu more to 3.7 or 3.8 so that my rams would cope up with tighter timings or is this a problem having rams fully occupying

I have already tested rams using mem diagnostic test of windows7 and all was fine passing 2 tests

you are running pretty high for stock Voltages..start bumping those V's one at a time.

this is gonna take a little while, you need to hit your CPU NB and your CPU V up .025 at a time and give it a try.

okay so I'll set it up lil bit

to overclockers forums!

Anyways... that's a very nice OC from 2.8ghz to 3.6ghz and with an unlocked core! You must be extremely lucky to have been able to do that. From what a lot of people say about the 720BE is that it OC's very well on stock voltage (1.3v) up to 3.5ghz, and a lot of people get to 3.7ghz - 3.8ghz. If I were you I'd read Dolk's PhenomII guide, it'll have all that answers you need!

Dolk's guide: here

It does seem rather strange to me that your ram wont run at stock timings and freq. since you have the stock 200mhz HTT. It could be that because you have 4 DIMM's of 2gb's each. It might not be that your ram is struggling, but your northbridge. I'd try slowly raising the vNB up +0.2v until you get stable, but don't go past 1.3v unless you have really good cooling. But read Dolk's guide first.

Dooms101 said:

to overclockers forums!

Anyways... that's a very nice OC from 2.8ghz to 3.6ghz and with an unlocked core! You must be extremely lucky to have been able to do that. From what a lot of people say about the 720BE is that it OC's very well on stock voltage (1.3v) up to 3.5ghz, and a lot of people get to 3.7ghz - 3.8ghz. If I were you I'd read Dolk's PhenomII guide, it'll have all that answers you need!

Dolk's guide: here

It does seem rather strange to me that your ram wont run at stock timings and freq. since you have the stock 200mhz HTT. It could be that because you have 4 DIMM's of 2gb's each. It might not be that your ram is struggling, but your northbridge. I'd try slowly raising the vNB up +0.2v until you get stable, but don't go past 1.3v unless you have really good cooling. But read Dolk's guide first.

Click to expand...

thats what im afraid of, whats the failure rate on it??

I had a 720 unlocked and set to 3.6 as well.
I think your problem lies with the memory. Very very few people can run at 1600mhz with resonably tight timings. Your better off runnig it at 1333 and 1T than to bother getting it stable at 1600. You will notice just as good of performance with tighter timings than higher speeds.

Good day to all again!

I've got good news...

Just finished prime95 blended test for 4hours - passed!
& small TFFS for 8hours - passed!

Here's my CPUz: http://valid.canardpc.com/show_oc.php?id=936435

Just what you told me,
I've bumped my vcore to 1.4 and vNB up to 1.225

My memory timing is at 8-8-8-21 2T (memory voltage= set to auto or i assume its 1.5v)
is 1T optimal for 4x2GB setup?
(BTW my bank cycle time is at 40, is this optimal or sluggish?)

and what's a good Dram ratio for 1600mhz freq, mine's got 1:4?
I've heard 1:1 is the best...

Thanks a bunch for welcoming me to your Forums, I really appreciate it.
& thanks to all who have replied.

My temps as of now utilizing speedfan and same with bios Idle=27 and Load=40
I think I could push my OC up to 3.7 or 3.8? what's your opinion

Well, those temps sound great for 1.375 vCore, and it' surprising that your CPU is stable at 1.375v (which is a good thing though), those ram timings are pretty good. 1T command rate is what almost all DDR3 runs at (DDR2 runs at 2T usually, DDR runs at 1T or 0T), as far as your 40 bank cycle time, it sounds fine.

To answer your question about the ram divider (also know as ram ratio), 1:1 ram divider with a 200mhz HTT (system bus frequency) yields DDR3-400mhz... which is not optimal in anyway for DDR3. Here's the formula for finding final dram frequency:

(HTT / (Ram ratio)) x 2

So using your current setup:

(200mhz / (1/4)) x 2 = 1600mhz

and using 1:1 is

(200mhz / (1/1)) x 2 = 400mhz

As you can see... 1:1 is not a good choice (nor do I think that option is possible in BIOS.) Here's some other popular ram ratios for DDR3:

(3:8) = 1066mhz
(3:10)= 1333mhz
(1:4) = 1600mhz
(2:9) = 1800mhz
(3:14)= 1866mhz (this isn't popular, but G.Skill has a kit using this)
(1:5) = 2000mhz
(2:11)= 2200mhz
(1:6) = 2400mhz

Thanks for a lot of information and literally explaining how to get the ratio,

I think I'll give it a try later on...

My motherboard is rated to withstand upto 1800mhz OC rams
but have you heard or tested having 4x2GB with AMD set up running at those frequencies?
I know my memory could easily go to 1800mhz cause its rated at 2000mhz, I've only downclocked it, but my problem is could my amd cpu and mobo fullfill it?

Well... I don't think the different Ram frequencies effect the CPU at all, and since your motherboard can handle 1800mhz, then there's no reason it wouldn't work. I am not an expert with the PhenomII's... so if you haven't read Dolk's Guide yet, then I suggest you. However, you should definitely be able to run at 1800mhz. As long as you set the stock timings to whats on the SPD for 1800mhz and have the right voltage. Some ram kits claim very high frequencies, but they don't mention at what voltage. So, if you're having troubles getting to 1800mhz, try adding 0.1v to the vDimm or even 0.2v.

I'll set 1800mhz later

Weird because when I accessed Bios manually you can set it maximum at 800mhz only x2 effectively thats 1600mhz only. Im going to see if adjusting the vdimm at 1.6 will make it thru 1800

Trying it out at 3.8
Hope unlocked 720be makes the cut

CPUz phenom II 720BE unlocked 4th core

http://valid.canardpc.com/show_oc.php?id=937078

BSOD after 3min. prime95

Agressively up vcore 1.525, nb 1.245, htt 2600mhz,

Well I am assuming you aren't using a graphics card? Without a discrete graphics card, your NorthBridge has to handle GPU calculations and therfore makes OC'ing a little tougher. I suggest you try this setup:

HTT: 225mhz
NB Multi: x10 = 2250mhz
CPU Multi: x16 = 3.600ghz then x16.5 = 3.713ghz
vCore: 1.500v - 1.525v
vNB: 1.25v
DRAM: (225 / (1 / 4)) * 2 = 1800mhz
vDimm: 1.70v - 1.75v
Timings: (9-9-9-32-1T)

You're right dooms101, I don't have a graphics card yet. Planning to buy 5870.
The settings you recommended didn't make it. It freezes before even reaching desktop.
Anyway thanks a bunch, I highly appreciate all your replies. As of now I'm satisfied at 3.6Ghz and it's unlocked. I will post soon when I've got a vC.