AMD Athlon 64: Newcastle chips are here!


"Tom's Hardware": and "Anandtech": both report on the new socket 939 newcastle core chips shipping. Here's a summary of performance:
* The Athlon64 3500+ at 2.2 GHz and 512 kB L2 cache probably is the most attractive new processor. With an initial price of around $500, it is more expensive than the Pentium 4 at 3.4 GHz. In exchange, it will beat Intel's top-of-the-line model in the majority of gaming and multimedia benchmarks except for video encoding.
* "Anandtech socket comparison": We did not expect large improvements in performance as Athlon 64 moved from 754 to 939. Since we have found the performance of the Dual-Channel Socket 940 and the Single-Channel 754 to be close when they ran the same speed with the same cache, it was already clear the Athlon 64 was not an architecture that was starved for memory bandwidth like the 'deep-pipes' Pentium 4 design. When P4 went dual-channel the performance improvement was dramatic. Athlon 64 shows more modest increases in performance, but that performance increase is still real and measurable with the 754 1-5% slower than 939 depending on benchmark.
* "Athlon 2600+ Coming": AMD will introduce a 1.6GHz part at some point soon. If its based on the latest CG stepping, it could overclock to 2.4-2.5GHz and be a great overclocking buy.
* "Xbitlabs Comparison": Echoes the results of the Anandtech review. Also points out that you have to be careful about getting memory that works in the "1T" configuration. The requirements are pretty specific. Its a big deal in that it increase memory bandwidth by 25% if you get the right memory modules. Overclocking is low for the 3500+ and 3800+ (2.2 and 2.4GHz respectively), with the new CG stepping, clock rate tops out at about 2.5GHz
* "Right Memory, Right Motherboard for socket 754": Exhaustive test of many motherboards and many memory chips for Athlon 64. It shows a complex "table": of compatibility. You do have to be careful in choosing a board that lets you run double-sided DDR memory. The MSI "K8N Neo": did particularly well and is a new nForce3 250 Gb chipset so has all the latest features.
Net, net, there aren't great performance differences between the 754 and 939, so it comes down to pricing. Interesting to see how much the cheaper 2800+ can overclock to on the 754.
At retail, athlon 64 list show the new Athlon 64s in the Socket 939 are finally here. Here are some prices from newegg that show you get about 5% performance increase going from a $404 3400+ to a 480 3500+. Not great, but a big deal for gamers I guess.
Right now, I'd say at these price levels, the 754 probably remains a good deal particularly the 3200+ overclocked to 2.4GHz, but that should change post introduction pricing.
| Chip | Socket | Frequency | Cache | Price | Core | Memory |
| 3800+ | 939 | 2.4 GHz | 512KB | $698 |
| Newcastle | Dual Channel |
| 3700+ | 754 | 2.4 GHz | 1MB | $689 | Clawhammer | Single Channel |
| 3500+ | 939 | 2.2 GHz | 512KB | $485 | Newcastle | Dual Channel |
| 3400+ | 754 | 2.2 GHz | 1MB | $404 | Clawhammer | Single Channel |
| 3200+ | 754 | 2.0 GHz | 1MB | $282 | Clawhammer | Single Channel |
As you can see based on this, the old Clawhammer (original Athlon 64) cores don't look too bad in price. There is a real premium for the 2.4 GHz versions. Reports are that you can overclock the Clawhammer 2.0 GHz up to 2.4 GHz, but not sure yet whether the new Newcastles can overclock even more. In any case at these prices, more of enthusiast line for now.
Not clear when Motherboards for 939s ship are in stock either.