Intel has released the next generation Nehalem CPU's.
The first generation, known as Bloomfield, comprises the i7-9xx series of CPU's.
The new generation is known as Lynnfield and comprises the i5 and the i7-8xx series.
So what does that mean for our new editing rig? Should we run out and opt for this new generation, or would we be better off with the established Bloomfield? Here are some initial thoughts.
The Bloomfield platform uses the X58 chipset and a LGA-1366 socket. The Lynnfield uses the P55 chipset and a LGA-1156 socket. That is an important difference, because P55 motherboards are less expensive than X58 motherboards. But, like Johan Cruyff used to say, every advantage has it's disadvantage. Next year we will be seeing the next generation CPU's, based on 32 nm technology, with 6 cores and hyper-threading. A simple BIOS update will allow these new CPU's to be mounted on X58 motherboards. That is not possible with the P55 boards. So, P55 is less expensive but also less future proof. X58 is more expensive but can also support the new 6 core CPU's.
On to the new CPU's.
The difference between the i5 and i7-8xx is hyper-threading. The i5 has no hyper-threading. Apart from clock speed they have the same architecture and the same TDP, 95W. In comparison to Bloomfield there are a number of distinctive differences. The two QPI (Quick Path Interface) links have disappeared. No more triple channel memory, only dual channel DDR3. In its place has come an on-die PCIe controller with 16 lanes. The Bloomfield supports 36 PCIe lanes, but not on-die. This is an important handicap of the Lynnfield archtecture, because it precludes the use of other multilane PCIe cards, other than the video card.
First tests show that the different memory controller does not have any relevant impact, whether triple channel DDR3-8500 on the Bloomfield, or dual channel DDR3-10600 on the Lynnfield is used. However, only the high-end P55 motherboards have 6 DIMM slots to allow 12 GB of RAM, other motherboards often have only 4 DIMM slots and are thus limited to 8 GB.
The new heatsinks still suck, so if you want to get this new CPU, invest in a good CPU cooler.
The Turbo mode has been significantly improved and Windows 7 has been optimized to use it to advantage with core parking. Turbo mode can give a performance increase of more than 10% with applications that are not multi-threaded. CS4 is multithreaded, so the advantage of the turbo mode is probably very small.
Lynnfields uncore is faster than Bloomfields, but the downside is that the on-die PCIe controller limits overclocking at stock voltages. Lynnfield is not good at overclocking, thanks to the PCIe being tied to BCLK, unless you increase vCore.
Intel positions these CPU's as mid level, not high-end and I think they did a good job. The CPU's are good and fast and leave all AMD processors in the dust.
The i5-750 is a great entry level CPU, it is nicely priced and delivers good performance, but lacks hyper-threading.
The i7-860 is on the same performance level as the i7-920, but more expensive, which can be offset by less expensive mobo's, with all their limitations. Also not as easily overclocked.
The i7-870 performs between the i7-940 and i7-950, but is easily beaten by an overclocked i7-920 for less than half the price.
All these CPU's do a good job, but the limitations are there as well:
1. Only 16 PCIe lanes
2. Stock voltage overclocking is lacking
3. No support for 6-core Gulftown CPU's
The major improvement with Lynnfield is the Turbo mode. That makes it even more difficult to choose Bloomfield or Lynnfield, because the Gulftown successor will undoubtedly improve on that even more and choosing Lynnfield now requires a new mobo and a Gulftown if you want to go the 6-core route.