Confused about i7 speeds

[InverseOfNeo]

I am looking to purchase a new desktop. I upgrade about every 5-6 years. Desktop is currently P4 2.53 GHz if that tells you anything. I'm not paying for all of it so I'd rather get something that is almost top of the line but not overpriced. I looked at the specs on Intel's website. http://www.intel.com/consumer/products/processors/corei7-specs.htm. From the looks of it the 860 (2.8-3.46GHz) is faster than the 920 (2.66-2.93 GHz). However, the 920 is priced (in a retail bought system) about $25 more. Is the 920 faster/better despite the lower clock speed? Also, I realize there are faster i7's out there that I can go to instead of the 860 (for example 870) or 920 (upgrade to 940), however those are hundreds more and I really dont see them being better and cost effective choices.

I know that there may be other sites that have benchmarked the two CPUs. However, I am sure that a number of you have already read them and can accurately and honestly answer my question. Thanks.

 

[Hey Zeus]

920 and 860 are two different sockets.

920 - 1366
860 - 1156

Look at the X3440. Has HT and is a hair slower then the 860 for about 60 dollars less

 

[Shilohen]

i860 and has turbo mode that auto overclock some of the core is some aren't getting used. Note that it's socket 1156.

i920 doesn't not have turbo mode, but is an overclocking monster. That one is socket 1366.

So, if you overclock, 920 is likely a better choice, get the 860 otherwise. The 860 also has better power consumption, dunno if that's an issue for you or not. Beware of the socket when you chose your MB.

You can find AT's 860 review that do the comparison with the 920 here: http://www.anandtech.com/cpuchipsets/showdoc.aspx?i=3641

 

[Lonyo]

The 860 is faster/better in pretty much all current situations as a CPU.
The only time it might be slower is if memory bandwidth comes into play in a big way, but for most typical consumer workloads, that's almost never going to happen in a meaningful way.

The main issue is PLATFORM.
The i7 860 is a socket 1156 chip which means you have dual channel memory and only 16 PCIe lanes for graphics, meaning Crossfire and SLI modes are limited to 8x/8x
With the 920 you get triple channel and 32 PCIe lanes, meaning you can do SLI/Crossfire with x16/x16, or even triple/quad(?) setups if you want.

Unless you are planning to do SLI or Crossfire in the future, this doesn't matter.
If you are, it still might not really matter, since the performance difference is minimal between 8x and 16x.

The other platform element is future CPUs.
If you do want to upgrade before 5~6 years, then the socket 1366 (920) setup will have better (and more expensive) CPUs available.
The 1156 (860) system will be more limited in terms of top CPU performance options available, but will have cheaper options (including more budget level offerings).

If you're not planning to upgrade for 5 years, the future CPU options won't matter either though.

 

[Jd007]

i860 and has turbo mode that auto overclock some of the core is some aren't getting used. Note that it's socket 1156.

i920 doesn't not have turbo mode, but is an overclocking monster. That one is socket 1366.

So, if you overclock, 920 is likely a better choice, get the 860 otherwise. The 860 also has better power consumption, dunno if that's an issue for you or not. Beware of the socket when you chose your MB.

You can find AT's 860 review that do the comparison with the 920 here: http://www.anandtech.com/cpuchipsets/showdoc.aspx?i=3641

i7 920 has the less aggressive, first generation turbo mode, while the i7 860 has the second generation turbo mode which pushes the chip even more.

Both chips are great overclockers. The key difference is actually not in the ability to OC but in the ability to handle multi-GPU setups. Socket 1156 is based on P55/H55/H57 chipsets, which uses the PCI-E controller on the CPU and only has 16 lanes. However LGA 1366 is on the X58 chipset which has 36 PCI-E lanes in total.

It's all fine when you are using just one GPU running at 16x. Starting at 2 GPU CrossFire/SLI, the LGA 1156 platform will run each of them at 8x while the LGA 1366 platform will run each still at 16x. So there is performance impact on the 1156 computer. With 2 GPUs the difference is not that big (10-15% decrease), but when it gets up to 3 GPU setups, LGA 1156 takes a big hit, sometimes even slower than 2 GPU setups. LGA 1366 will handle 3 cards much better with its 36 total PCI-E lanes.

 

[InverseOfNeo]

So bottom line, the 860 might be better for me in the short term. However, if I decide to go Crossfire/SLI in the near future the 920 would be a better choice. And in the long future, it may offer me a better upgrade path.

 

[Lonyo]

So bottom line, the 860 might be better for me in the short term. However, if I decide to go Crossfire/SLI in the near future the 920 would be a better choice. And in the long future, it may offer me a better upgrade path.

I wouldn't call it a better upgrade path, I would call it a higher top end performance, more expensive, fewer options upgrade path.

Current Socket 1366 choices:
4 cores, 8 threads, $300~$1000
Total 3 CPUs. (effectively at the moment, 920/950/975)

Current Socket 1156 choices:
2C/2T to 4C/8T, $90~$550
Total 10? CPUs.

Socket 1156 will have the lower performing parts, but there will be more possible upgrade choices and at a wider variety of price points.
Socket 1366 is the high end enthusiast platform and isn't supposed to ever really have affordable or "value" products. It will get the 6 core/12 thread CPU first, but it won't be cheap. That's the sort of future upgrades you wold be looking at for it.

 

[Zap]

And in the long future, it may offer me a better upgrade path.

Does that really matter for you? You know that your Pentium 4 2.53GHz has an upgrade path too, right? However, the fact that it's been so long that they aren't available (new) and you are persuing a platform upgrade instead of a mere CPU upgrade should tell you something.