We're getting into the battle of size again with AMD and Intel. If you remember, the last time we left off with this competition based on clock speeds, prior to AMD's Thunderbird release, AMD had just released the 900, 950 and 1GHz Athlon parts, and in response, Intel made their 1GHz Pentium III parts available in "limited quantities" before releasing their 850 and 866MHz processors.

The release of AMD's Thunderbird and Duron processors in June created a welcome break from the seemingly month to month release of new CPUs that simply carried a higher clock speed. In fact, during the course of just 6 months, from October 1999 to March 2000, AMD released 7 different clock speed Athlons to compete with the 5 Pentium IIIs that Intel thrust forward into the marketplace. We all complain about the quick pace at which the graphics card industry moves, but can you imagine how loosely we would hold onto our sanity if NVIDIA released a higher clocked GeForce2 every month?

On the other hand, this constant flow of processors from the big two that are currently running the show has kept prices very reasonable. Just four months ago, having a 1GHz processor in your system meant spending around $1,000 or more on your CPU alone, thus reserving the chips for those that truly needed the power and those that had the ability to spend more than 1/3 of the cost of their computer on their CPU.

AMD has definitely been a proponent of bringing the performance market segment down in price but up in actual speed. With their most recent price cuts, AMD not only holds the title of the first company to offer the first 1GHz desktop CPUs but also the first to offer their 1GHz chips, in quantity, at below $500. To the end user, and the average AnandTech reader, an AMD Athlon "Thunderbird" running at 1GHz can be had for the price of NVIDIA's latest graphics solution, plus or minus a few bucks. But it isn't the very high end where AMD has brought us very pleasant prices -- an 800MHz Thunderbird can be had for $200 or less and an entry level Duron running at 600MHz is already being advertised at below $70. Each of these processors, from the highest 1GHz parts to the lowest 600MHz Durons features the same 200MHz FSB (100MHz DDR) and 133MHz memory bus support that demonstrate AMD's approach to differentiating between their products.

The Sunnyvale based company is back for another set in this clock speed tennis match that has been going on intensely for the past year now with senior rival, Intel. Intel most recently took control of the spotlight with their annual Fall developer's forum in San Jose that introduced, in more detail, the NetBurst architecture that will be powering their forthcoming Pentium 4 processor. In addition to that revelation, Intel's Pentium III family gained a new member this July, weighing in at a far from cute 1.13GHz, marking Intel's departure from the 50MHz clock speed increments and moving onto the 133MHz increments that each following Pentium III will jump up by.

It was the release of the 1.13GHz Pentium III that forced AMD to respond with their 1.1GHz Thunderbird today. If you remember, AMD had the Thunderbird running at 1.1GHz back in March at their renegade hideout (read: Hotel suite) outside of Intel's Spring IDF in Palm Springs, CA. We knew back then that the Thunderbird was capable of hitting 1.1GHz, but it wasn't until there was a clear need for such a processor that AMD thought to bring the beast out of training.

With Intel leading the clock speed race, it's AMD's turn to respond with their second four digit speed demon clocked at 1100MHz. Let's look at the newest member of the Athlon "Thunderbird" family.

The Chip

The 1.1GHz Athlon "Thunderbird" (from here on referred to as the Thunderbird) doesn't boast any new changes over the previous Socket-A Thunderbirds other than the increased clock speed.

· 37 million transistor 0.18-micron Thunderbird core with Copper interconnects
· 1.1GHz (1100MHz) clock speed - 11.0x clock multiplier
· 128KB on-die L1 cache running at core speed
· 64-bit exclusive 256KB on-die L2 cache running at clock speed
· 462-pin Socket A EV6 CPU interface running at 100MHz DDR (effectively 200MHz)
· 1.75v core voltage

As you can tell by the above specs, nothing has really changed with the 1.1GHz Thunderbird. If you're interested in learning more about the above specifications feel free to read our original Thunderbird review.

The 1.1GHz parts will most likely be produced exclusively in AMD's Fab30 plant in Dresden and thus will feature copper interconnects. As we mentioned in our Duron review, currently, the only way to differentiate between a Thunderbird manufactured in Dresden with copper interconnects and one manufactured in Austin with aluminum interconnects is by looking at the tint of the die itself. AMD uses a different polisher at their Dresden plant than they do at their Austin plant, the result being that all CPUs that come out of Dresden have a bluish-purple tint, which is what you will see on the 1.1GHz processors.

CPU Specification Comparison
	AMD Athlon			Intel Pentium III		Intel Celeron
Core	K7	K75	Thunderbird	Katmai	Coppermine	Mendocino	Coppermine128
Clock Speed	500 - 700 MHz	750 - 1000 MHz		450 - 600 MHz	500 - 1133 MHz	300 - 533 MHz	533 - 600 MHz
L1 Cache	128KB			32KB
L2 Cache	512KB		256KB	512KB	256KB	128KB
L2 Cache speed	1/2 core	2/5 or 1/3 core	core clock	1/2 core	core clock
L2 Cache bus	64-bit				256-bit	64-bit	256-bit
System Bus	100 MHz DDR (200 MHz effective) EV6			100 - 133 MHz GTL+		66 MHz GTL+
Interface	Slot-A		Socket-A Slot-A (OEM only)	Slot-1	Slot-1 Socket-370		Socket-370
Manufacturing Process	0.25 micron	0.18 micron		0.25 micron	0.18 micron	0.25 micron	0.18 micron
Die Size	184 mm^2	102mm^2	120mm^2	128mm^2	106mm^2	153mm^2	106mm^2
Transistor Count	22 million		37 million	9.5 million	28 million	19 million	28 million

AMD has updated their Ordering Part Numbers (OPN), which can be used to identify the specifications of any of their PGA processors. The more simplified code is described below as well as a picture of the markings from our 1.1GHz part:

Cooling the Chip

No one is going to argue that the Thunderbird is a very hot CPU. At 1GHz, the processor was already capable of dissipating up to 54W of heat, and at 1.1GHz, the maximum has been increased to 55W while drawing around 35 amps of current at 1.85v (maximum voltage).

Needless to say, cooling this processor requires a bit more than a tiny heatsink/fan combo, below are some pictures of exactly what AMD used to cool their sample 1.1GHz processors:

Click to Enlarge

Click to Enlarge

The 300g heatsink was a very tight fit over the 1.1GHz processor, it applied quite a bit of force onto the chip itself, much more than the heatsinks we are used to. It'll be interesting to see what a 1.4GHz Thunderbird would require in terms of cooling.

Overclocking

There are a number of motherboards available that support FSB as well as multiplier adjustment in order to pave the way for overclocked Duron/Thunderbird systems. Such boards include the ABIT KT7-RAID and the ASUS A7V, unfortunately, the motherboard can't do everything, in order for the motherboard to be able to take control of the CPU's FID and BP_FID multiplier pins, the "Golden Bridges" present at location L1 (below) must all be connected.

Most newer CPUs will be like the 1.1GHz shown above, where the bridges present at L1 aren't joined. In order to join them, some conductive epoxy or a very fine tipped conductive pen can be used to connect each one of the four bridges. Afterwards, your motherboard, provided that it does have multiplier control, should be able to adjust the clock multiplier of the CPU.

A Thunderbird with the bridges at L1 connected

There have been reports of Socket-A CPUs that feature even more attempts to prevent remarking, however we have yet to see any evidence of this first hand. We will keep you posted on anything we do discover.

Test Notes

• Since the 1.13GHz Pentium III is only available in a Slot-1 form factor we weren't able to run any i815 tests on the CPU as all of the i815 boards we have in the lab are all Socket-370.

The Test

As a gauge of overall system performance in business and content creation applications, SYSMark 2000 puts the 1.1GHz Thunderbird at about 5% slower than the 1.13GHz Pentium III. As you can tell by the scores above, SYSMark 2000 greatly favors CPUs with a fast L2 cache, as well as those CPUs that have a large L2 cache. Case in point would be the clear 10% performance advantage a 1GHz Thunderbird with its 256KB on-die L2 cache running at clock speed holds over an equivalently clocked K75 Athlon with a 1/3 speed off-die 512KB L2 cache.

You'll also notice that the Duron, clock for clock is about 3% slower than the older K75 Athlons and about 12 - 15% slower than the Thunderbirds again, on a clock for clock basis. Compared to Intel solutions in the same price range, primarily the Celeron, the Duron completely dominates because of its [effective] 200MHz FSB and 100/133MHz memory bus compared to the Celerons 66MHz FSB and 66MHz memory bus by default. Even when overclocked, the Celeron is still noticeably slower than the Duron on a clock for clock basis yet is comparable in terms of price. The only factor that is holding the Duron back here, and has apparently been hampering sales is that Socket-A motherboards aren't as prominent as Socket-370 solutions and they are noticeably more expensive than some of the cheaper Socket-370 boards.

From an Athlon vs Pentium III comparison, the performance between the two chips (Thunderbird vs Coppermine) is very close, but when it comes down to price, the Thunderbird is the more affordable solution.

Quake III Arena has always been dominated by the Pentium III and because of the overclocked BX133's incredible memory performance combined with the 133MHz FSB, the 1.13GHz Pentium III on an overclocked BX platform makes the demo001 benchmark approach an incredible 200 fps.

The 1.1GHz Thunderbird isn't too far behind, but what you have to realize is that the majority of gamers don't play at 640 x 480 x 16, instead they find themselves being characterized by the results in our next test:

Notice a lack of deviation from around 80 fps? That's because this test is being limited not by the CPU, not by the FSB and not by the memory bus. Instead, at 1024 x 768 x 32, the GeForce2 GTS proves to be the limiting factor as the card itself is memory bandwidth limited. If you own any of the processors on this chart, even those that may be slower (unless you're stuck with a 66MHz FSB), your best bet would be to upgrade your video card before you even touch your CPU.

You can run most of today's 3D games just fine on a Pentium III 500 or an Athlon 500, as long as you have a fast enough video card.

UnrealTournament scales quite nicely with CPU speed which makes it the perfect benchmark in a CPU review. On identical platforms (VIA KT133 vs 133A - they use the same memory/AGP controllers), the 1.1GHz Thunderbird is just barely slower (0.2 fps) than the 1.13GHz Pentium III.

The breakdown of performance is pretty similar to what we've seen before. The Duron, clock for clock is about 3% slower than a K75 Athlon and at 1GHz, the Thunderbird offers a 11.4% improvement over the original Athlon that broke the GHz barrier.

Unlike what we noticed under Quake III Arena, UnrealTournament doesn't seem to be choking the test GeForce2 GTS card at 1024 x 768 x 32. Instead the performance drop between 640 x 480 and this higher resolution is minimal, a faster CPU still seems to yield greater performance.

Under Expendable, the 1.1GHz Thunderbird is able to sneak up right behind the fastest platform in the roundup, the 1.13GHz Pentium III on an overclocked BX133 platform.

The performance breakdown is similar to what we've seen previously, except this time the Duron is considerably slower than even the K75 Athlon. An overclocked Duron running at 900MHz is around 9% slower than an equivalently clocked Athlon, but the Thunderbird doesn't offer a huge performance increase over the regular Athlon. Expendable is an example of a situation where a larger L2 cache is favored over a faster one, meaning that the 128KB L1 + 64KB L2 cache of the Duron isn't enough for Expendable, meaning that the CPU must go all the way over to main memory at either 100 or 133MHz in order to gather data. Both of the Athlons, with their 128KB L1 + either 256KB or 512KB L2 cache perform much better since they aren't running all the way over to the system memory for data as much courtesy of their larger L2 caches.

In spite of this disadvantage, the Duron remains dominant over its chief competitor, the Celeron which is still heavily penalized by its 66MHz FSB. Even when overclocked using the 100MHz FSB, the 850MHz Celeron is still barely able to hop in front of the Duron running at 600MHz.

Once again, the Pentium III vs Athlon race is very close, performance is nearly identical, the deciding factor here should be price.

Content Creation Winstone 2000 paints us the same picture we've seen all along. The 1.13GHz Pentium III is barely faster than the 1.1GHz Thunderbird and depending on the platform, it could end up being slightly slower, the main thing to keep in mind is that the performance of the two solutions is so close that you need to turn to comparisons based on other factors to make your decision. The other factors to take into consideration are availability, price, and cost of the motherboards. In two of those categories, availability and price, AMD has most definitely had the advantage in recent history.

The above benchmarks illustrate the potential of the Duron to be an excellent entry level processor, however it is still lacking something the Celeron has. We'll talk about exactly what that is in the conclusion, for now let's move onto High End performance...

High End Winstone 99 has always been appreciative of the Athlon's performance, and once again the 1.1GHz Thunderbird and the 1.13GHz Pentium III are within a few tenths of a point of each other. It is interesting to note that the VIA Apollo Pro 133A chipset seems to produce scores that are very competitive with the overclocked BX chipset running at the 133MHz FSB.

Here, the Duron is only 1 - 2% slower than the K75 Athlon and about 7 - 12% slower than the Thunderbird which is pretty impressive considering you can pick up one of these CPUs for under $70. This just continues to prove the recent axiom that High End doesn't have to mean expensive.

Quake III Arena under Windows 2000 provides a breakdown of performance very similar to the benchmarks under Windows 98, the only difference is that we can see a small performance boost because of Windows 2000.

Once again, the GeForce2 GTS is the limiting factor here, not the CPU nor the platform it is running on. If you find yourself with a 600 - 700MHz CPU and want better gaming performance, consider a new video card before you examine the path of a new CPU.

SPECviewperf has always favored the Athlon processors, and for some reason even the 1.1GHz Thunderbird can't come close to the performance set forth by the 1GHz K75 Athlon. We usually attribute this to the K75's larger L2 cache and its ability to cope with larger data sets, whereas with enough data, even the 256KB L2 cache of the Thunderbird can become a limitation. The case of the latter happening, as you can see from most of the benchmarks that we have been running is highly unlikely because of the extreme performance advantage the Thunderbird's L2 cache holds over that of the K75 Athlon.

The Duron seems to perform very well, considering its intended price point, in most cases the processor is only a couple of percent slower than the Thunderbird at the same clock speed.

The Thunderbird regains its performance advantage over its older brother in the DRV-06 viewset, and the 1.13GHz Pentium III is close on its heels. Even the Duron remains competitive with the K75 Athlons.

 

Distributed computing tasks such as RC5, once again, proves to be entirely dependent on raw clock speed and not upon L2 cache, memory bandwidth, etc... For more information about RC5 and how you can join AnandTech's RC5 team click here.

Conclusion

AMD has kept up their end of the competition, releasing a faster clock speed Thunderbird for every Pentium III released that challenges its domain. But as we've seen in the past, clock speed doesn't mean everything, in the end there are a number of factors that you have to take into consideration that will ultimately decide what CPU is right for you.

First of all, if you have older peripherals, hard drives, etc... that could be slowing you down, upgrading to a faster CPU won't yield the incredible performance improvement you're hoping for. As our Quake III Arena benchmarks have shown, in some cases there was no more than a 5 fps difference in performance between a 600MHz Athlon and a Thunderbird running at 1.1GHz because of the fact that the video card was limiting the overall performance of the system. So definitely make sure that there are no other bottlenecks, or very few, present in your system before considering upgrading to one of these CPUs.

Secondly, if you find yourself with a solid BX board, the upgrade is simple. As long as your motherboard supports the Pentium III, you'll be much better off just making that upgrade since you don't have to worry about the cost of purchasing a new motherboard. If you aren't satisfied with your current platform, then the number of upgrade options increases.

The Socket-A market is definitely a growing one. The Thunderbird is very competitive with the Pentium III and AMD has shown, through the release of their 1.1GHz Thunderbird that they can keep up with whatever clock speeds Intel may throw at them, all while making sure that their CPUs are actually available in more than just "limited quantities." The Thunderbirds are noticeably cheaper than their Pentium III counterparts, the only downside is that Socket-A motherboards can be somewhat expensive. We have seen prices fall a bit, however our top picks for Socket-A motherboards are both priced above $150, while prices will come down, for now that is the only drawback.

Motherboard prices aren't hurting Thunderbird sales as much as they are impacting Duron sales, why? Remember that advantage we mentioned earlier in the review that the Celeron still holds over the Duron? You can currently put together a Celeron + i810 motherboard combo and have a very low-cost system, but for the Duron, there is currently no integrated video solution to compete with the i810. While it may not be that big of a deal to most hardware enthusiasts that don't really want integrated video, it is a very big selling point for an entry-level Celeron system, a very low price point What point is there to having a $70 processor when the motherboard will cost system integrators twice that? AMD desperately needs VIA's KM133 (KT133 + integrated Savage4 video).

So there we have it, the Thunderbird is now past the 1GHz barrier, how far will it go this year? Will the introduction of the Mustang core end the Thunderbird's recent reign as AMD's flagship core? This fall should hold some powerful CPUs from AMD and Intel. With the Pentium 4 due for an appearance later this year, it'll be interesting to see if AMD positions the Thunderbird to go head to head with the P4 or appoint a new Mustang variant to handle the job.

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