Crucial 256MB PC2700 DDR
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Date Posted: May 28, 2002

probably doesn't need any introduction. Well known for producing high quality memory, it's no wonder that so many OEMs use their brand. Launched November 1996 by Micron, the company was made for the end user/consumer to buy ram direct from the same place OEMs buy it. This assured compatibility as well as competitive pricing. Crucial cooks their own ram right here in North America, and being one of the largest memory manufacturers worldwide contributes to their low prices.

A little late to the market, Crucial was one of the few companies that waited for the to ratify a PC2700 standard. What does this mean? Instead of pretenders with their overclocked PC2100 to PC2700 modules, Crucial's memory is true PC2700. Granted, we've been able to overclock some of our PC2100 modules to 166FSB without too many problems, but true PC2700 ram should run more stable, and perhaps overclock even higher.

Used heavily as the memory of choice by AMD, Intel has recently adopted DDR as their mainstream performance memory. RAMBUS is still preferred by Intel for the power user, but given it's court and mass market adoption woes, DDR looks to be here to stay. With processors increasing in speed, a faster memory interface was needed, with the current standard now being PC2700.

For those of you who need a refresher, here's a snip from our past review of DDR...

So what exactly is DDR? It's an acronym for Double Data Rate (or Ram, depending on who you ask), where it can process information on the rise and fall of any given clock cycle, and it's not limited to just the rising edge like it's predeccesor. Basically, it can do twice the work of regular SDRAM (Single Data), though in real world scenarios, it isn't twice as fast. DDR isn't as much as a new technology as it is an evolution of existing SDRAM. It's been around long before being introduced as a replacement for SDRAM. Starting with the original GeForce DDR, most modern video cards today use DDR, and it was only a matter of time before it made it's way to motherboards.

Unlike other manufacturers, Crucial uses a 6 layer PCB, rather than 4 like other manufacturers. Don't worry about compatibility, as it is withen specifications, and will fit any DDR motherboard. Here's a bit more off their site...

"The terms "4-layer" and "6-layer" refer to a module's printed circuit board (PCB)--the green plastic board that holds the memory chips. In general, the more layers a PCB has, the better."

A 6 layer PCB should provide a cleaner signal, and more stability. When motherboard manufacturers use additional layers, the price tends to be higher, but Crucial continues to be among the better bargains online.

Specifications

" DDR PC2700

" CL=2.5

" Unbuffered

" Non-parity

" 6ns

" 2.5V

" 32Meg x 64

A few terms some of you may be unfamiliar with, and that are important are the PC2700, Unbuffered and CAS Timings (CL) markings. All of this is indicated on a sticker on the ram module.

PC2700 (DDR333) refers to the bandwidth available for the ram. At the moment, PC2700 is about as fast as it gets for DDR, but as you may be aware, there are several brands of overclocked modules available.

Unbuffered is the type of ram. Buffered ram is typically only for servers or workstations where more redundancy is needed. In most cases, unbuffered is fine, but if you plan to load your PC up with ram, be aware that some motherboards cannot handle more than two DIMMs of unbuffered ram (usually).

CAS, which is an acronym for Column Access Select (or Strobe depending who you ask), is rated at 2.5. CAS is the number of CPU cycles for the ram to take to retrieve and to process information. The lower the number, the better, but in some cases more unstable. 2.5 is a conservative rating that should run most reliably. Right now, CAS 2 is the fastest timing available.

Crucial was kind enough to send us the sample of their final product. At 6 nanoseconds (-6T marking), this is equal to ~166MHz (333DDR). Should you purchase some Crucial memory today, these should be the markings on your memory. We ordered a couple more sticks to verify. Why am I making such a big deal out of this? You'll now see benchmarks from a final product, and not some cooked engineering sample.

Overclocking

In the past, we've had some good success with overclocking our Crucial PC2100, and I didn't expect much to change. The first test was to simply drop our memory into our , and make the appropriate change in the BIOS. We kept all our tweaked settings as is.

The ram should now be running at 166FSB, tweaked as well as we've done in the past with PC2100. The result? Not so good. The system successfully posted, but halfway during the Windows bootup, we were presented with a BSOD, then an immediate reboot. I tried a couple more times, and by the third reboot, I was forced to reset the CMOS. I tried a variety of settings, and keeping all the settings as you see in the picture above, I lowered the CAS latency to 2.5. We successfully got into Windows, so I tried changing the other settings, but putting the CAS back to 2. Again, blue screens were frequent, and I can only conclude that at 166FSB and up, CAS2 was not going to work. For the record, I tried this with one DIMM (we normally test with two), and I tried each of the other DIMMs I purchased, and no luck.

Afterwards, it was time for some traditional overclocking. I'll get more into it in my KT3-Ultra review next week, but a 143FSB overclock was the best I was able to manage out of the board. This is regardless of the multiplier, so 143+33=176FSB, which is the best memory overclock I was able to manage. Here's the rest of our results...

12.5 x 143 = Pass

12 x 143 = Pass

11.5 x 143 = Pass

11 x 143 = Pass

10.5 x 145 = Pass (Windows lockup)

10.5 x 144 = Pass (3D Mark lockup)

10.5 x 143 = Pass

10 x 144 = Pass (Unstable)

10 x 143 = Pass

That was all at CL2.5. We also kept the ram asyncronous to the system clock, to verify it wasn't the ram holding us back. I also swapped in some Kingston PC2100 ram, and the results were the same.

I shouldn't have to tell you this, but Crucial has a pretty strict policy on overclocking. If you bust your ram doing this, well, the problem is yours.

Benchmarks

AMD Athlon XP 1800+ (1.75v)

MSI KT3 Ultra-ARU

2 x Crucial PC2700

Windows XP

SiSoft Sandra

Now, on to the tests...

Crucial CAS 2.5, 133FSB, Memory Speed Fast

Our first test was done at a FSB of 133. I figured that if it didn't work here, we'd be in serious trouble. The scores aren't anything special, and fall in line with the PC2100 scores we're used to around here.

Crucial CAS 2.5, 166FSB, Memory Speed Fast

Bumping up to 166FSB, there is a noticable improvement in the scores, though I had expected to crack the 2000 mark for SiSoft. I've actually scored better with tweaked PC2100, so I wasn't terribly impressed at this point. It's time to get the memory timings off "SPD" in the BIOS and start doing this manually...

Crucial CAS 2.5, 166FSB, Tweaked, Memory Speed Ultra

As expected, the SiSoft scores get a nice kick in the back, but we're still not in the 2000 range yet. At this point, we've done everything we can do without actually overclocking the ram, so by bumping up the host clock to 143, we'll run at host clock + 33...

Crucial CAS 2.5, 176FSB, Tweaked, Memory Speed Ultra

Now we're talking. I think the chart speaks for itself, but I know a few of you are probably wondering what kind of numbers should we expect from tweaked out, overclocked PC2100 ram? Well, we reset our CAS latency to 2, and kept everything else the same. Since we're limited to 143FSB, this was our result with some Crucial PC2100...

The extra 33MHz provides about a 2% gain. Hmm, not exactly a huge jump, but if it was slower, I'd have a real problem with that. Certainly, improved overclocking would certainly change the numbers, and I'll tell you for certain that PC2700 ram will likely overclock higher than PC2100. Our system wouldn't even boot when we overclocked our Crucial PC2100 to 166, so the value of true PC2700 is apparent here.

Final Words

Well, to be honest, if you already got a killer PC2100 system, there isn't much point of upgrading to PC2700. To get the most out of the PC2700 ram, you'll need to upgrade your motherboard to a DDR333 motherboard, which you may have seen in other reviews, don't drastically improve on decent DDR266 boards. Then again, if you're still riding on the SDRAM bus, it's time to get off and move onto a DDR setup. At this point, there really isn't any point going for anything slower than a DDR333 rig.

That's all I have to say for mainstream users. Power users on the otherhand probably already have a DDR33 motherboard, so it's a matter of finding the right ram. I have seen 190+ overclocks with Crucial's memory, and through our testing, albeit not as aggressively overclocked, our memory has been rock solid. Crucial does lack some ramsinks, which may or may not make a difference, although I did find the module quite warm after testing. Another thing power users will like, after draining their wallet on other high-end gear, is that Crucial's ram is quite cheap when compared to others. Now before you flood my inbox with prices of other manufacturers being lower, remember that if you live in the US, shipping is free. It's also fast, as the ram only took a few days to arrive.

Crucial Technology: Pros: Good performance, decent overclocking potential, good pricing, and better shipping. Excellent quality.

Cons: CAS2 @ 166FSB just wasn't possible.

The Bottom Line: Crucial's ram, in theory, should run more reliably, and produce fewer memory related errors since it's built on a 6 layer PCB process, and is officially JEDEC approved. They're also not a fly by night operation, and have tech support that will actually provide tech support. Remember that, as a lot of "PC2700+" ram probably doesn't fall within specifications. How important is this? Probably not much if you simply use your computer for recreational purposes, but for number crunchers and workstations, you better get reliable ram. Benchmarks only tell one side of the story. Running SiSoft 100 times doesn't mean anything if it fails to run the 101st time.

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