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AMD K7 interview with Drew Prairie

Posted: May 6, 1999
Written by: Keith "Farrel" McClellan

I had the privilege of interviewing Drew Prairie from AMD about its newest processor - the K7 (a.k.a. Intel's Greatest Fear). This interview is jam-packed full 'o goodness, so read on.

Tweak3D: For those readers who don't know, who are you and exactly what do you do at AMD?

Drew: My name is Drew Prairie and I work in the PR department at AMD.

Tweak3D: What sets the K7 apart from, say, the upcoming coppermine core PIII's?

Drew: There are a number of technical advances in our 7th generation processor, and the surrounding platform, that differentiate K7. I'm a bit hesitant to compare K7 to other non-shipping CPUs since I'm not sure how those CPUs will perform once they do reach the market. The features we have disclosed publicly (and I can talk about at this time) include: 200MHz system bus with scalable multiprocessing support based on the Digital EV6 bus , 128KB L1 cache (64K instruction, 64K data), support for 3DNow!, deeply pipelined nine-issue superscalar core, and a superscalar 3-way pipelined floating point unit. The K7 was also designed to operate at speeds faster than 500MHz based on our .25-micron process technology, so we plan for the speeds to ramp nicely.

Tweak3D: What are the proposed processor speeds for the K7's at release? How fast do you anticipate a speed increase over the first K7's?

Drew: We haven't disclosed any speeds for launch time, have to wait till the summer on that one. As for how fast it can go, we have stated several times it is our plan to introduce a 1 GHz processor in the year 2000 using .18-micron process technology and copper interconnects.

Tweak3D: The K7 has been acclaimed as the first true 7th generation processor. What features/specifications are attributed to a 7th generation processor?

Drew: See above for a pretty good rundown of the technical features of note. Basically though, this is our latest processor designed from the ground up to provide superior performance to the processors currently available based on 6th generation cores.

Tweak3D: I understand that the K7 will be running on a non-Intel chipset. What features of this chipset make it superior to the 440BX and the upcoming 440JX (Camino) chipsets?

Drew: Actually, we have been running on a "non-Intel" chipset since the move to the Super7 platform (100MHz FSB and AGP support). We haven't gotten into the details of the initial K7 chipset, which will be an AMD product, but we plan to make sure the chipset can handle the requirements of the K7 and the K7 platform. ALi and VIA have also announced plans to offer K7 chipsets in the future. They are in a better position to talk about the specific features their chipsets will support. We plan for additional infrastructure partners to announce support for the K7 platform when the processor is available this summer. As for how it compares to future Intel chipsets, I don't think the specifics of those have been released officially yet --- so I can't really even offer a general comparison. All I can say is that we know what we need to offer a competitive platform.

Tweak3D: It is my understanding that the L2 cache on the K7 will be at 1/3rd the processor speed. How will this affect performance and will there be versions of the K7 processor with a faster cache? Also, I heard an unconfirmed rumor that the K7 may include an L3 cache - is this true, and if so, how will it affect performance?

Drew: We haven't disclosed what the L2 cache speed (or size) will be at launch time. Don't think of K7 as a single product, but as a product family that can scale to meet various market requirements. Because the L2 cache speed is programmable, you can then imagine various versions of the K7 with differing cache configurations (the K7 can support up to 8 megs) and access speeds (full core speed, half-speed, 1/3 speed, etc). I hadn't heard the L3 cache rumor, but as rumor I can't really comment on it. Can say though that there are lots of rumors out there, and there is something to the old adage of believing half of what you read.

Tweak3D: In certain previews, similarly clocked PIII's and K7's have had very, very close benchmarks (not using any processor specific instructions). How do you respond to such articles and will the K7 be faster than the PIII by the release date? Are these speed factors related to the BIOS, a bottleneck concerning the use of non-bus speed RAM, or the actual chip design?

Drew: Any review you read on the web of the K7 is using pre-production versions of not only the K7 module, but the motherboard, the chipset, drivers, and the BIOS as well. It would be like comparing a released movie with the rough cut version. All of the pieces are there and look good in the rough cut, but they have not been put together into a neat little package that is ready to be viewed and compared with other completed products. We haven't released any benchmarks on the K7 yet, but when we do you can expect for us to demonstrate seventh generation performance. Stay tuned. ;)

Tweak3D: Will the K7 processors be multiplier or frequency locked? Also, will bus frequencies higher than 200 MHz be attainable on the K7 motherboards?

Drew: We have no plans to lock the multiplier or frequency. Although we have made no announcements about future bus frequencies, the EV6 bus is currently available in a 400MHz implementation.

Tweak3D: The K7's chipset has the unique ability to "down-clock" the memory bus down to 100 MHz so that users can use PC100 RAM. Will the motherboard support faster RAM and how? At release, will there be any bus speed RAM (200 MHz) available for high-end systems? If not, will it support the 133 MHz RAM that is being produced for the 440JX chipset?

Drew: I don't know if "down-clocking" is the right word, either technically or descriptively. The 200 MHz system bus for the K7 is the speed at which the system logic and the processor communicate. All other system buses, memory/AGP/etc, are not tied directly to this 200MHz operating speed. The net result is that the CPU/system logic bus can operate at 200MHz and the memory bus can operate at 66/100/133/etc. MHz without any problems --- alleviating any bottleneck between the chipset and CPU that may be in place today. Another cool thing about the EV6 bus architecture is that in MP configurations, the CPUs have point-to-point connections with the chipset and do not have to share bandwidth. Support for additional types of memory is tied to chipset support. We have not disclosed any info on our initial chipset and neither ALi or Via have given any details on the chipsets they have in development. That said, if we want to continue offering a competitive platform versus the other CPU guys, there are a number of technologies we need to make sure the K7 platform supports. Faster memory technologies are definitely on that list....

Tweak3D: I have heard rumors that all 200 MHz RAM being produced for the K7 will be Rambus RAM. Is this true and, if so, how do you respond to the reports that because of worse CAS latency settings, this RAM isn't as fast as standard SDRAM at the same speed? Also, how would the worse CAS latency affect the overall speed of the system?

Drew: We haven't made any announcements about using Rambus RAM. The only thing we have said is that we have a license to the technology. Anything else you may have heard is just rumor, and I can't respond to rumors.

Tweak3D: Will the K7 chipset support the AGP 4x standard? In the past, non-intel chipset boards have had problems with sub-standard AGP implementation - will this be a problem with the K7 chipset?

Drew: We haven't made any announcements about AGP 4X support in the initial K7 chipset we have developed. AGP 4X is one of the technologies that the K7 platform will need to support. As for implementation problems, we learned a lot with the Super7 infrastructure development and we are working hard to make sure the same issues are not repeated with the K7. When there are some many variables (different chipsets, different graphic cards, different motherboards) it is always difficult to make sure every combination possible performs flawlessly. That is always the goal, and is something we have many dedicated resources working on.

Tweak3D: Thanks Drew - I appreciate your help. The K7 looks to be one of the most promising processors of the year. We will probably receive a test system sometime soon after its release, so check back here for more K7 action.

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