Can you talk a bit about the clock speeds you will be choosing for your products? What reasons do you have for choosing those? This includes memory and of course the graphics clock.
Steve Mosher: "What clock speeds will we ship products at? First off, I'm not going to break any news on upcoming products. EVERY supplier of TNT2 and Ultra TNT2 will ship a product that out performs any of the Banshee2 (AKA, Voodoo3) products. Every supplier of TNT2 products will ship cards that look better and perform better than the Banshee2 (OK, Voodoo3). Having said that, we take a no compromise approach to our performance products.
The process of determining what speed to ship boards at must consider the following issues:
A) What is the warrantee clock rate?
B) What is end user demand?
C) What is the competition doing?
D) How fast can we go?
E) What is the cost/benefit of going faster?
In the high-end product segment, where performance is a premium, we design our boards for speed first and cost second. We want to provide headroom for end users that like to fiddle with the clock, although we don't encourage overclocking. So our high-end boards are designed with plenty of margin for overclocking. That is an engineering decision. So if the memory clock of the chip were warranted to 183MHz, we would lay the board out for much faster operation. These kinds of layouts tend to cost more (including fans), but some customers will pay for this added benefit.
The second issue is qualification of components. A high-end board may be designed for 230MHz operation, but in selecting memory then you may have to set a standard operating frequency of less than 230 MHz because of variations in the memory supply. Every component, the board, the chip, the memory has process variation. So memory spec'ed for 183MHz may vary in speeds from say 183 to 195, for example. Moreover, the memory may vary from vendor to vendor and from lot to lot. That means memory from company X MAY, on average, run faster than memory from company Y, more importantly, one lot or batch of memory from company X may vary from another batch of memory from company X. The reason why the memory vendor provides a spec is to ASSURE that 100% of the product operates at the stated frequency. Some percentage will ALWAYS run faster, but which parts will run faster and how much faster is a Lottery. When a vendor finds a good portion of the parts running faster, they create a new speed bin.
The third Issue is the clock rate you decide to ship the product at. This is an end user warranty and end user experience issue. So you can design a board to operate at 230MHz, qualify memory at 215MHz, and decide to ship it with a setting at 200 MHz, because of warranty issues. For example, if the memory was spec'ed at 200, you might decide to ship it at 200, even if your testing showed it could go to 215. Now why would you do this?
A. Any testing of component lots is a statistical process. Fifty boards may pass testing at 215 MHz, but this testing is only statistical. No failures in fifty boards, is not 100% confidence of no failures in a million boards.
B) You may want to preserve your warranty claims against a component supplier."