The Celery Report: Overclocking the Celeron

I test each CPU under initial identical conditions prior to "burning in" my combos. I do an initial test run using the same Abit BH6, same RAM (single stick 64MB Micron, CAS3) and the same video card, a Trident 975, 4MB AGP. For those who are interested, this is a very fast 2D card that consistently scores better than 5 in Final Reality. Not very good in 3D, but for a business system, it’s a screaming bargain. I use an old 270MB Quantum hard drive (actually have 3 set up identically, so I can burn multiple combos at once). I use an old hard drive because I assume that these setups will be going in to a variety of situations with a variety of drives and that if it’ll work with this clunker, it’ll probably work anywhere.

I run a quick test at 450 using Business Winstone 97. Why such an old version, you might ask? Because I’m not testing for performance, only stability. This works perfectly for that purpose. If it fails, I bump the core voltage up a notch until it passes. If the CPU won’t do 450 or requires more than 2.2v core, I set it aside for later evaluation. After passing the first test on my evaluation board, I move the chip to the motherboard with which it will be mated.

I put each one through 6 full rounds of Winstone and 2 hours of Final Reality. By using these two tests, I’m covering both the 2D business users and the 3D gamers. As an aside, for those who haven’t used it, Final Reality is not only a great test, it is visually stunning. One glitch at current voltage, and it’s bumped up a notch, until it’s completely stable. Because I believe that stability means no excessive measures, I don’t call a chip good if it requires more than 2.2v core to stabilize. I like a little breathing room.

Each report will consist of two parts. First will be the results from testing since my last report, and second will be cumulative totals. I will also include any new discoveries, such as what I’ll shortly be revealing here for the first time.

This week I tested a total of 24 Celery sticks. These were all SL2WM (OEM), all Costa Rica. Before I move on, let me re-address a couple of myths. First, there is no difference in overclockability between Costa Rican CPUs and Malaysian CPU’s. If this were true, there would never be a failure with a Malaysian chip because the Costa success rate is very, very high. Second, the same applies to OEM versus Retail. They are exactly the same stepping and core. You do, however, get the longer warranty with retail.

I had two separate 12 unit batches of chips. Using the white label on the back as our guide, the first were week 46 and the second were week 45. Of the first, I’m further dividing in to 2 batches of 6; in a minute you’ll see why.

The first half of the first batch were a disaster (that may be too strong a term, they worked, just not at 450; getting a little greedyJ ). Four of the six CPU’s flatly refused to do the 450 dance and the other two required 2.3v to run stable. This is a very low percentage based on past experience. Of the second half of this batch, all did 450 quite easily at 2.2v or less.

Of the second group of 12, all did 450Mhz and eleven of them did it at default voltage of 2.0! I began to wonder why there was such a dramatic difference in performance both within the same week and between the two different weeks. I’ve previously reported encountering difficulty with CPUs that were mounted on a darker green shade of PCB substrate, but I now realize this is only part of the equation.