Anyone have  insight to the performance gains the E8400 (with it's 6mb of L2) delivers to "DNS experience" as compared to the e6750 or other 4MB L2 CPUs?

Good question. I'm curious too.1

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There are several distinct advantages of the 8000 series Core2™ Duo is over the 6000 and 7000 versions

1.  The 8000 series are 45 nm chips vs. the 6000 and 7000 series 65 nm chips.  This means they run cooler and faster in a smaller footprint.

2.  The 6000 and 7000 Core2™ Duo is cannot share L2 cache across both CPUs.  That is, in the 6000 and 7000 Core2™ Duo series you have a fixed cache assignment of 2 MB assigned to each CPU (CPU 0, CPU 1).  If CPU 0 runs out of L2 cache it can't borrow from the L2 cache for CPU 1.  The 8000 series Core2™ Duo's can share all 6 MB of L2 cache and does it very efficiently.  Because it's L2 cache that increases performance and speed, there is a very noticeable speed advantage with the 8000 series over the 6000 and 7000 series Core2™ Duo chips.  In addition, several new instruction sets in the 8000 series make more efficient use of both RAM and L2 cache.  This is particularly true if you have multiple documents, for example, open in Microsoft Word.  This is due to what is generally called enhanced piping, and generally means that the 8000 servers will find the most efficient route in utilizing both the L2 cache and RAM from each channel (dual channel) in creating the parallel processing path and piping data, instructions, etc. through the most logical and efficient path.

3.  Given the above, the cost/benefit of the 8000 series far outweighs that of the 6000/7000 series.  There is no significant advantage to going to the 8500 vs. the 8400 because you will not find any significant increase in performance relative to the cost difference.  However, be 8400 is currently running about $200 and some change.  The 6000/7000 series is about the same.  So, why buy a Volkswagen when you can have a Cadillac for the same price, or at least approximately the same price.

4.  The 8000 series runs at an FSB (Front Side Bus) of 1333 MHz and will utilize both DDR2 running at up to 1066 MHz, as well as (depending upon motherboard) the ability to support the new DDR3 RAM when it becomes available.  The 6000 7000 series supports a maximum of 1066 MHz FSB (Front Side Bus) and a maximum of 800 MHz DDR2 only.

Does this mean that the 8000 series is significantly faster and perform significantly better than the 6000/7000 series?  Noticeably yes, significantly <???> probably not statistically significant.  Nevertheless, my new 8500 outperforms my old Q6600 Core2™ Quad by a fairly good margin, but is significantly slower in overall performance and speed compared to my Core2™ Extreme Quad Core QX9650.  Nevertheless, the 8000 series is an excellent purchase for the cost minded/performance needy DNS user.  I don't think most users are ready to spend $1200 on the Core2™ Extreme Quad Core QX9650.

Chuck Runquist
Former Dragon NaturallySpeaking SDK & Senior Technical Solutions PM for DNS

Good tactics can save even the worst strategy. Bad tactics will destroy even the best strategy. - George S. Patton

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Chuck this is an edit to my post - I reread your respose and realized you have answered my questions. If you care to expand on how the new instruction set might be used within DNS and what aspects of perforce will be improved, I would enjoy the knowldge transfer.

 

First, thanks.

Second, from a benchmark or less formal hands on trial are the gains noticed in speed of response or accuracy?

Third, I remember your detailed post comparing DNS performance running on 6000 series dual vs. quad, I wonder if could comment on the e8400 relative to that comparison.

Fourth, thanks again

Chuck:

I am going to build a new system in the next couple of months.  In terms of performance I am only concenred about two things, fast handling of large data files and my No 1 priority, having DNS work really well.

Moreover, I was thinking "Real Men have $1,000 CPUs", so it was nice to learn I could spend about $700 less.

So your advice is invaluable and many thanks.

  --  Julian


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-- Julian

Julian Nott www.NOTT.com DNS 12 Premium KnowBrainer 2012 Windows 7 16 8GB memory Ivy Bridge i7-3770K

Chuck:

 You may want to double check your specs. The E6850 ( 65 mm process, 3.0 GHz dual core) has a 1333 FSB and, unless Intel changed their specs recently, DOES allocate the shared L2 cache between cores as needed. That (shared cache) is the only truly revolutionary aspect of the dual core thing. The problem Intel quads have been fighting is an antiquated cache-sharing system which can bring that processor to its knees if swamped by low-level tasks (performed using FSB and RAM rather than the shorter, faster on-die circuitry).

I agree with most of the rest of your well thought out replies on this issue. 

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chuck, that's great info about the 8000 series core duo chips.  my aging home desktop is about to be replaced (i'm typing this on the laptop, so it won't know) and i've been looking for info specifically on the q6600 quad core vs. high-end dual cores. first-person experience like yours is especially valuable.

i know the gamers talk about various mobo's being better, but they're talking about overclocking. since my relatively new lenovo desktop w/ an athlon 64x2 3800+ dual core w/ 1mb L2 is really fast and accurate, the system w/ an intel core duo 8XXX ought to blow its socks off (i hope). of course, if you have any suggestions (i.e., faster ddr2, 2 vs. 4 gb memory, faster hard disk) now would be a great time to find out, before i pull the trigger on the purchase.

thanks again for the good info. having you participate here is one of the main reasons i come back (tho' i'm usually lurking).

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