Which FC-PGA Celeron to overclock?

[Patrick]

I have some questions regarding overclocking on an Asus CUBX board.

I currently have PC100 RAM and a Celeron 366@550 on this board. With the cost of CPUs and RAM dropping the way they have lately, I'd like to now upgrade to a faster Celeron and PC133 RAM. My questions are:

1) Should I get a 66MHz bus speed Celeron (533, 566, 600, 633, 667, 700, 733, or 766) and run it at 100MHz?

Or...

2) Should I get a newer 100MHz bus speed Celeron (800, 850, or 900) and run it at 133MHz? (I've heard the CUBX board will supposedly run at that bus speed with the "right" RAM.)

In either case, which of these Celeron chips have the best chance at being overclocked successfully? Keep in mind that with the CUBX board I'd be needing an FC-PGA processor.

Thanks for any feedback.

[Guru]

If I were you I would go with a 566 or 600MHz and o/c it using an 100MHz fsb!

[Patrick]

That was a quick response! Any reasons in particular for your suggestion, Guru?

[ayoub_ibrahim]

been hearing from a reputable source that the 800MHz cDO stepping celeron is quite an o/clocker with quite a few reaching 1.2GHz with only a small increase in default voltage. mind you, your AGP speed wil be well out of spec!

[Guru]

Originally posted by Patrick
That was a quick response! Any reasons in particular for your suggestion, Guru?

Only that it's almost 100% certain that those cpus will overclock using the 100MHz fsb (850 and 900MHz)!

+ as ayoub_ibrahim says both your ram and agp speed will be out of spec if you are planing to rais the fsb over 100MHz!

[Patrick]

I've included a link to a local store that I've shopped at to show the current CPU prices here (in Canadian dollars). It's interesting to note that the OEM Celeron 566 sells for $129.95 whereas for a few dollars more you can buy an OEM Celeron 850 (complete with VOLCANO III fan) for $134.47. Or how about this- a retail Celeron 800 for $23.28 less at $106.67!!! I don't understand this. It's beginning to make me wonder if there is any real benefit in overclocking the slower chips at all.

http://www.ncix.com/Canada/ramcpu.cfm

[Jon P. Inghram]

I'm running an 850 at 950, 112 FSB on a CUBX with no problems other than having to disable the PoS UDMA/66 controller. I'd run it higher but I don't feel like taking a chance that the high AGP speed might trash my G400 MAX. I used to have a 533A in it, but the annoying voltage bug (1.6v max, otherwise board wouldn't even POST) didn't let me o/c it over 800, and even then it wasn't 100% stable. The new celerons default at 1.7 or greater and thus don't have a problem on the CUBX. I bought my 850 in a retail box from a local computer place for 104.95.

[edit]
Oh, and I'm running two 128 meg sticks of generic PC133 RAM at CAS2, they'll run fine at 133 MHz CAS3 but not CAS2.
[/edit]

[Patrick]

Jon, you've grabbed my attention with your comments regarding the onboard ATA/66 controller on the CUBX. I've just recently connected another drive to it and I'd like to continue using it along with my FastTrack raid and it's two drives. Is there a known problem with it running at bus speeds of over 100MHz?

On the same subject, does anyone know whether a Matrox Mill/2 AGP video card on the CUBX board would be happy at higher bus speeds, say maybe 133MHz?

[Maggi]

Originally posted by Jon P. Inghram
I'm running an 850 at 950, 112 FSB
...

Basically I run the same CPU here, but I bought mine as a 566 and upped the FSB from default 66.6 to 112 MHz ...

To make a bit clearer, I bought a 66.6MHz FSB Celeron II 566, a long time before Intel decided to sell those same CPUs for running at 100MHz FSB. They use the same core, same multiplier and thus I definately recommend to buy a 66.6MHz FSB CPU and let it run at 100MHz FSB or even above.

I suspect that even the higher clocked Celeron 667 will run at 100MHZ, resulting in 1GHz core frequency.

[MK]

Because some onboard RAID controllers seem to be very picky concerning the FSB speed, I would not take the risk of using significantly more than 100 MHz FSB on the CUBX.

My recommendation would be a retail FC-PGA Celeron with 667 or 700 MHz (both with default FSB 66MHz) and o`c them to 100 - 105 MHz.

Generally use retail Celerons for overclocking, the average success rate among them is higher.

Additionnally have a close look on the s-spec of the CPU you are going to buy. Have a look at www.overclockers.com -> CPU databases and look for the good s-specs in the 667 & 700 MHz section (mine is a "SL4P2" - I can strongly recommend that one).

MK

[Jon P. Inghram]

The CMD controller started acting flaky when I upped the FSB to 112. For example, while playing Diablo 2 I'd suddendly get a "Cannot write to drive C:" error, forced me to reboot. Then when the computer rebooted scandisk said the drive may have developed bad blocks. I ignored it and went on using the computer until I got two more of the write errors. I then turned the FSB back down, ran a full scandisk on both my drives (slllloooooowwww, 40+10 gig, and of course no bad blocks), and decided the problem is very likely the HDD controller. I moved everything back onto the native controller and put the FSB back up to 112 and have had no problems since.

[edit]
Hehe, about buying a 850 instead of a 566 I was simply sick and tired of stability issues with my 533A running at 800 and just wanted a very reliable chip that'd o/c without even a hint of complaint. Now I'm running it at 133 FSB, 1.13 GHz, nice and stable. Had to bump the memory back to CAS3 though, but otherwise it's just fine. But I won't leave it here because it gets too hot in the room and I don't wanna fry my mobo, G400, or CPU...
[/edit]

[Patrick]

This thread has turned out to be quite informative for me (and hopefully many others). Thanks guys.

I would like to continue to use the onboard CMD ATA/66 controller on the CUBX, so finding out that this controller is not happy at a FSB above 100MHz is valuable information. This effectively narrows down my Celeron overclocking choices to the 66MHz units (and using a FSB of 100MHz).

I find it interesting that the 66MHz Celerons mentioned so far are the slightly slower ones. Is there a specific reason why the faster 733 and 766MHz chips can't be run as "easily" at a FSB of 100MHz?

I also suspect that a lot of these chips are getting harder to track down as they get "old". I was disappointed to see that the Celeron 700MHz CPU is not even listed anymore at the link I posted earlier.

[MK]

Patrick - here in Germany respectively Austria the 700 MHz Celeries are pretty easy to get ...

MK

[Demo]

I have been running a 533 @ 100Mhz and 1.7V 24/7 for months with no problems, it is rock solid. I use a golden orb to cool the thing.

I think the batch number has a lot to do with the clockability of the things so as suggested above check it out at overclockers.com