This is the first time I have ever over clocked a CPU and I have got my E6300 up to 2.24GHZ just by altering the FSB from the default 300 to 320.

The performance improvement is certainly noticeable but from what I've read I should be able to get to about 2.5GHZ with stock cooling.

The problem is when I increase the FSB any higher OSX won't boot. I've tried different increments in the FSB but the same thing happens each time, ie, in verbose boot the system halts at "still waiting for root device". As soon as I back down to 320, it boots fine.

This is probably my lack of O/C knowledge, but should I be making any other changes in the BIOS as well?

Any help or suggestions would be appreciated. Thanks.

Well, at a guess its your RAM holding you back. but also there are a few things you can do in your BIOS. Your ratio RAM to FSB helps, on my MOBO i have the ratio set to 2:2 so so 400 FSB = 800mhz (RAM) if you have the ratio set to auto the mobo sets the speed far to far when OCing and you will not boot into anything...

Not being able to boot into an OS is a sure sign of having gone to far. scale back. slowly push your FSB forward in .5 increments ensuring your RAM ratio is set 2:2. get into OSX and run a bench loop it a few times... if your still running and your temps are acceptable go back and push a little further. DDR6400 (800mhz) ram would allow you to push alot further then you will be able to with your 5300.


RAM is cheap rite now, head over to Overclockers UK and pick up 2gb of DDR6400 or 85000 if you can afford it. The Gigabyte Mobos OC well and i think you could get a little more out of it.

You could also try increasing your V.core a tiny amount. be carefull when playing with volts your temp will rocket and you could kill your CPU.


HOPE that helps.


J.

I would add that with your board when you first go into the BIOS use the CTRL + F1 keys at the same time so you will see your ram timings when you enter the overclocking option. Now once in there set the PCI-e bus from auto to 100 then the ram multiplier to 2X your FSB to 343 now go down to the voltages section and up the voltage by +1 or +2 for the ram making sure the timings on the ram look sensible something like 5-5-5-12 or 15 now this should get you ~2.4GHz once saved and rebooted. Once you get into OSX you will want to run the attached mprime program to stress test you machine to make sure the overclock is working well. To use simply extract the files change into the directory and use ./mprime -m answer the setup questions declining the offer to join choose only run stress tests then option 1 smallfft if it will pass this for more than a few hours then your good to go and you will want to use the Temperature Monitor (to big to upload you need to search for this) program to check the temps they will be at least 15C higher than they are because the program is only designed for chips that a Mac uses which have higher rated temps you would need a G0 chip to get proper temps not the B revision you have.


Edit: I should add that to stop the mprime in the terminal window then you need to use the CTRL + C keys at the same time then choose exit the program choice number 5 I believe.

Just want to say thanks to both of you for your fast, detailed responses. I will give your advice a go this weekend and let you know how I get along.
Thanks once again for your support.

I had a try with your suggestions.

First, MacBook Joe, the RAM to FSB ratio was already set to 2 so I couldn't get any further on that track.

MacUser2525, I went into the CPU Frequency & Voltage section and pressed Ctrl+F1 but all I get is a general help window. Also there is nowhere I can see that enables me to change the voltage. I can change the PCI-e bus to 100 by setting it to ASYC, but the voltages are shown in a different section and are all non editable. Maybe my mobo doesn't support making changes here?

Any further thoughts would be welcome. Do you guys think faster RAM is my best option and would buying 8500 over 6400 be worth it given that I am using the stock heatsink so won't be pushing the CPU too far?

Thanks again.

Yeah if your board is limited like that then your probably better off with the 8500 if the board will support it, now for the faster ram it would not really make a difference you want it running at 1:1 most times anyways so a 1333mhz chip like the 8500 only requires DDR2 667 ram to do that so both of them would be operating on a 333mhz stock bus... 4x for the Quad pumped CPU and 2x for the double data rate ram its a perfect match for each other this way make sure your board supports the 8500 @333mhz though or you will be wasting your money.

Either we're at cross purposes or I am just not understanding your last reply. I was referring to 6400 0r 8500 DDR2 RAM not CPUs. I was looking for advice on whether the RAM speed would give me the overclocking of my E6300 that I am looking for.

Thanks

Ok I did mis-read the post well PC8500 ram is a total waste really you need the FSB running at 533mhz for a 1:1 ratio for it vs full ram speed which is what you want according to almost any guide I have ever read. PC6400 would suit you better but I would check by lowering your multiplier to 6 then raising your ram/FSB you have now to 333mhz to make sure your board is even able to do a FSB that high otherwise the PC6400 will be a waste as well as your board will not overclock past that point anyways.

Ok thanks, that helps a lot as there is quite a price difference between those two types of ram. I'll have another go later today. In the past, when I've tried altering the multiplier as well the PC has just rebooted and put the settings back to default, which is why I've only altered the FSB this time.

So at the moment I've upped the FSB to 320 (default 266), so I assume that means my multiplier is still around 7 (6.95) to give me my current clock speed of 2.24Ghz? Is this stressing my current ram?

You think I should try a multiplier of 6 and an FSB of 333. Am I correct in thinking that would give me a clock speed of 2.0Ghz on my CPU? I understand this is just to test whether the FSB will run at that level.

Am I getting this? The bit I don't understand properly is the relationship the ram speed has on things.

Thanks again, this is a good learning process for me and I appreciate your input.

Exactly the 6x 333mhz is running your ram at its rated speed so not stressing it all if your board won't do this without error then there is no use buying newer faster ram as you will never get the chance to use it at anywhere near its rated speed in that board. The ram speed/FSB your machine runs at gives you your final cpu speed with your multiplier so in theory PC6400 ram rated FSB speed is 400mhz so if your running it at its rated speed you would end up with 2.8ghz (7x400) or if lowering the multiplier 2.4ghz (6x400) the ram you have in their now PC5300 is rated for 333mhz now in order to do the 2.5ghz you want/need your present ram to run at ~357mhz. Now to get it to run at 357 you may if it is possible with it/your board need to probably up the voltage on the DDR2 maybe + .1 or .2v and maybe up the voltage on the MCH just a little bit one or two of its over-volting settings if any in your BIOS. Where the PC6400 comes in handy is with it you should not need to up any voltages if your board will do a high enough FSB my present e6300 for instance in a Gigabyte 965P-S3 board will do 3.01ghz (7x430) running stock voltages using PC6400 ram.


Now I am pretty much convinced that any Core2Duo chip will run at ~3ghz on stock voltages with the C1E and PM2 enabled no Speedstep it screws up the overclock, as I have done this with four different chips 2 e6300 and 2 q6600 in three different boards (Gigabyte 965P-S3 v1.0, 965P-DS3 v3.3 and P35-DS3L v2.0) as long as your FSB on the board will run high enough to get that speed. This is reguardless of the VID (default voltage hard wired into the chip it will run at) my old e6300 had 1.325v the new 1.2625v the old q6600 had 1.3v the new 1.2125v this runs at 3.15ghz the others all capped out at the 3ghz. Of course to run this high you need good cooling but even with the stock cooling the old e6300 I have in a machine I am selling of to a buddy of mine runs at 2.4ghz using PC5300 ram (7x343mhz in the 965P-DS3 board) with the temps in the high 30C idle mid 50C under full load if he wants to upgrade the cooling and ram to PC6400 then he can hit the 3hz without problems if the ram will do that (430mhz FSB) if not guarenteed 2.8ghz running the ram at its rated speed.

Hopefully this is not too confusing for you at this point basically you want to know the highest FSB your ram will do in your board then see if it will run at 7x multiplier at that speed without putting a lot of extra voltage to the chip because once you change the voltage from normal on the CPU itself instead of the ram or MCH (ram controller chip) the C1E will not work anymore. The C1E is what will keep your chip cooler as it will lower the multiplier and voltages at idle automatically putting it back up to the chips normal settings when the load on your machine needs to have it.

I'm getting 2.78 GHz on my chip. Running very stable. Thats the max I can get my board to but with a better board it can go higher and still be stable. I'm using DDR2 800 factory over clocked to 1000.

I'm getting more confused by the minute after my latest attempts.

I altered the FSB to 333, the only memory multipliers I can apply are "auto, 1.5, 2.0, 2.5". I was set to 2.0 when the FSB was 320 resulting in the CPU running at 2.24ghz.
With the FSB at 333, I left the multiplier at 2.0 which gave a memory speed of 667. When the system rebooted the CPU speed was showing as 2.33ghz.
As I expected, OSX failed to boot hanging at "still waiting for root device", however the PC did boot into Windows XP. This is where it got more wierd.
I ran CPU-Z and for a few seconds it showed the CPU speed at 2333mhz then changed to 1998mhz and a multiplier of 6, which is what we were trying to achieve I think.
When I looked at My Computer>Properties, that showed the CPU running at 2.33ghz.
Confused or what?
Clearly the mobo will handle 333mhz FSB, which is what we needed to establish, and CPU-Z backs this up, but I don't understand why the BIOS shows the CPU running at 2.33, as does Windows, CPU-Z also shows this briefly, then changes to 1.998ghz. More frustrating than all this though is that I can't get OSX to boot with the FSB set any higher than 320.
What do you think? Lost cause?

Thanks again.

That is the C1E it drops the multipler and voltage to the chip unless it is under load now if you want you can disable it but your chip will run at full voltage all the time and yes I think your stuck with the 320 unless higher voltages will get the job done.

So just to be clear, would higher rated ram say PC6400 make any difference? Also, any thoughts on why I can boot into Windows at 2.33ghz but not into OSX?

Thanks again.

Higher rated ram is no good to you unless your boards FSB will run higher than 333mhz that is the rating for PC5300 the PC6400 is rated at 400mhz so you would want your FSB running >333 and <400 to use it properly. You can always buy and put it in there hardware is a mysterious thing sometimes who knows with it your FSB might hit the 400mhz I seriously doubt it will but you never know. For the windows vs OSX my q6600 will boot into windows and run fairly well for surfing and such at 9x400 for 3600 hell it will even go to 3800 or 9x425 but it will not run under any type of load doing these speeds. So my question is did you actually do any stress testing once booted in the windows? If the OSX is putting more stress on the system when booting then this can cause the failure.

Hi MacUser2525

No I didn't put any stress on the system whilst booted into Windows. As you've said, it looks like I've reached the end of the road for overclocking with this particular motherboard. I think I'll just be grateful for what I've managed to squeeze out of it already. It certainly makes OSX run a lot zippier than at the stock speed.

If I were to stick with Gigabyte, what would your motherboard/ram recommendation be for one up from budget level of what's available now? Also what do you reckon is the best sensibly priced CPU to put with it - I'm thinking around £100? And finally, can you recommend a good resource on the web to learn more about overclocking without bogging me down too much?

Thanks for all your help over the last few days.

Yeah unfortunately it does look like that is as high as it will go.


You may want keep what you have for the CPU if only wanting new motherboard, now if your really wanting to get new CPU then you may as well get one of the new 45nm chips like the e8400,e8200. For the motherboard something like I have the GA-P35-DS3L (got it for $88 Canadian) this would be if you can live with only 2 SATA ports working AHCI mode with fix that supposedly works in IDE mode for all 4 ports here in the forums. Or you could go older generation GA-965P -S3 or -DS3 these will give you four ports AHCI using both the Jmicron and ICH8 ports on the board, all these boards support 45nm chips with latest BIOS flashed/installed. For a guide take a look at the one below.

http://www.anandtech.com/cpuchipsets/intel...?i=3184&p=1

Since you will be overclocking don't forget to upgrade your CPU cooling if your case will fit it then the Thermalright Ultra 120 Extreme is one of the best they make smaller 92mm version or you could go with an Arctic Cooling Freezer 7 Pro this is a good one too.



Your welcome.

With that board, you are doing well to get as far as 320! According to Gigabyte, they see 1066 (266) FSB as the maximum rated speed, and the Rev 3.3 version of that board considers 1066 (266) as an overclock as it is!

The 945 chipset was only made with a 266 FSB in mind. AsRock made some tweaks with their ConRoe 1333-667 945-based board to get a stable 333, but that is with the PCI-E bus overclocked by a fair margin so not quite ideal. The Bus/RAM dividers give up at over 266, and you have to make do with what you have.


If you were to try a different chip, you could have some luck with the E2xxxx/4xxx series of CPU. They run with a far higher multiplier, due to them only being a 200 FSB, so you have more headroom FSB-wise. Bear in mind though, you may have to do a BSEL mod (Google is your friend here..) in order to reach a default 266FSB (which will set memory/bus speed dividers up nicely for the next step..) and you are still voltage limited due to your board not supporting manual voltage.

So if your E2/E4 craps out at, say 275FSB (which on an E4300 still gives you 2.75Ghz), you're stuck with attempting to raise the CPU speed any higher unless you are prepared to do some further pin mods (bit trickier than a BSEL mod due to the location of the pins you need to bridge) on the CPU itself in order to raise the default voltage.


However, and here's the crunch, you won't get much change from your £100. An E4600 (200FSB, 2.4Ghz core speed, 2Mb cache) will set you back around £90 and, if you don't have much luck with the overclock, you're not getting *that* much of an increase over what you are running at the moment.

Finally, a decent overclock, even with voltage modification is not guaranteed with *any* CPU. Ok, some have a better rep than others, but it's not set in stone...

A friend of mine bought an E4500 and ASUS P5K-VM board in the hope of getting some scary core speeds out of it. Every man and his dog appears to be able to get these north of 3Ghz, according to some forums, and yet he is struggling, even with heroic voltages, to get above 2.6Ghz (default 2.2Ghz), whereas my lowly 1.8Ghz E2160 runs happily, if a bit warmly on a standard cooler, at 333FSB which gives me 3Ghz. (I keep it at 300FSB, 2.71Ghz at the moment until I can get around to buying a better CPU cooler). Upon further forum-trawling, we found quite a few posts from people having similar issues, buying an E4500 in the hope of getting an instant 3Ghz+, and having to settle for 2.xxxGhz as the CPU just ran out of steam.

It's not his board or RAM that is holding him back, as we tried dropping my E2160 into his board and it fired up happily, and ran stable at default voltage for a good few hours at 3.2Ghz. Could have tried for even higher, given the default voltage, but time was short and I wanted my CPU back!

Personally, in your situation, I would try a better motherboard first, see how far that E6300 of yours will really go. It'll be a bit cheaper at first, give you a platform to upgrade further into the future (quad-cores are getting more and more affordable at the moment), and then, if you do upgrade your CPU later on, you can build a cheapy 2nd system out of the bits. Jobs a goodun!


So, there you are. A bit of a black art sometimes, but good fun nonetheless if you don't mind a few potential headaches along the way.

<fx: sits back, makes rollup, rests fingers, drinks tea>

Thanks for the interest and extra info Lozzo. I think your advice is sound, I have a very capable Hac right now where pretty much everything is solid and the speed is not unrespectable, xbench 129 including the disks. I think I'll stick with this for now. The only trouble with leaving it alone is I have to do some proper stuff on it rather than tinkering! I sometimes wonder what a computer is really for.
Looks like I'll be diverting my attention to my recently purchased but noisy 7900GT card to see if I can shut it up.
Thanks again, enjoy the tea & rollup!

Zalman 900-cu aftermarket cooling for the GT best $50 I ever spent it is damn near silent at anything but it highest speeds and it lowered my temps on my 7900GS KO 10C at its lowest setting compared to stock cooling from E-VGA.

That's the one I have in my cart at Tekheads.co.uk for £27, so that's good enough for me. Hopefully these things are as simple to install as a CPU cooler.

Cheers!!

Oh yeah damn simple to install you take off the old cooler use some Isopropanol Alcohol 99% to clean the ram and GPU stick on the ram heatsinks screw in the post that go through the board put the washers on them flip it over and screw down the holders on the back then you done of course putting on the included thermal compound on the GPU great little rig I tell you. Oh you do need a free three pin fan connector on the motherboard to get power to the fan so check you have that before buying.

Good shout about the fan connector, I think my board only has one spare and it's in use by a case fan. I should be able to get some kind of splitter from Maplins to adapt one of my spare leads or the fan header.

Something I meant to ask about your Gigabyte board. Mine has front audio header which I've connected to the case jacks with the HD cable but I don't get any sound out? Do you have yours working or is that something that Macs just don't do? It would be really handy to be able to plug in a mic and headphones, say for skype or chat.

Thanks again.

I don't think you can get them going I got tired of the 2 speaker sound anyways so I bought a Griffin FireWave box to get 5.1 surround sound via firewire as I had a couple of cards laying around that work perfectly, Dynex brand 3 port with the Agere L-FW323-06 chipset if anyone searching or you want to know. Now I tried the other day to use the on-board back of motherboard mic-in with my mini-jack plug headset but it would not work so I have been thinking of looking around to see if a USB set is compatible. Also you can get a 4 pin molex to 3 pin fan adapter to power the GPU fan or even put the case fan on it with the GPU on the motherboard one.

Edit: Did some searching apparently Griffin has an iMic you can get connecting via USB gives you the headphones out, mic in, line in and line out works with a windows PC as well. Just bought one refurbished on Ebay for $14.49US + $8.99 shipping to Canada, ships to the UK too the sellers ID is appleprostore 10,000+ feedback if your interested in this as well the Griffin site has it BNIB for $39.99.

http://www.griffintechnology.com/products/imic/