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*Dean Saadallah
Message 1 of 16 (2,113 Views)

Intel Core i5 and i7 CPUs

2113 Views, 15 Replies
09-08-2009 08:05 AM
Anyone with thoughts on these beasts? Best pairings with video cards?
Assuming we all agree Win7 64bit is the only way to go of course, Vista64bit
as a stop-gap measure. Optimum RAM? What is just right vs. too much to
really appreciate the difference. Budget +/- US$2k.

Assume usage to be AutoCAD Architecture 2010 for 2D drafting, 3D and
Renderings, 3DMax Design occasionally, touch up with Photoshop for static
images.

--
Dean Saadallah
http://LTisACAD.blogspot.com
--
*John Mayo
Message 2 of 16 (2,113 Views)

Re: Intel Core i5 and i7 CPUs

09-09-2009 12:31 PM in reply to: *Dean Saadallah
Have you seen this?
http://beingcivil.typepad.com/my_weblog/2009/08/new-video-understanding-performance-using-civil-3d.html


--
John Mayo, PE

Core i7 920 6GB DDR3
Radeon 4870HD 1 GB
Vista64
*John Mayo
Message 3 of 16 (2,113 Views)

Re: Intel Core i5 and i7 CPUs

09-09-2009 12:43 PM in reply to: *Dean Saadallah
I would go with Win 7, the i7 and I think you would need 12GB of ram with
triple channels. Video cards are big one. I see these $100-$200 Geforce
cards performing similar to a new Quadro FX 1700 ($500) but I would expect
some changes to the CAD cards soon. I would bet if you build it & go with a
Geforce you would come in well under $2k. Specs below were $1400 with Vista
64 upgrade & MSOffice upgrade.

Note I am not doing extensive 3d work.

--
John Mayo, PE

Core i7 920 6GB DDR3
Radeon 4870HD 1 GB
Vista64
*Matt Stachoni
Message 4 of 16 (2,113 Views)

Re: Intel Core i5 and i7 CPUs

09-09-2009 03:22 PM in reply to: *Dean Saadallah
On Tue, 8 Sep 2009 15:05:17 +0000, Dean Saadallah
wrote:

>Anyone with thoughts on these beasts? Best pairings with video cards?
>Assuming we all agree Win7 64bit is the only way to go of course, Vista64bit
>as a stop-gap measure. Optimum RAM? What is just right vs. too much to
>really appreciate the difference. Budget +/- US$2k.
>
>Assume usage to be AutoCAD Architecture 2010 for 2D drafting, 3D and
>Renderings, 3DMax Design occasionally, touch up with Photoshop for static
>images.

Be careful about specifying your Core CPUs. There are now two different versions
under the Core i7 "Nehalem" microarchitecture: the "Bloomfield" and the new
"Lynnfield."

Bloomfield CPUs are of the original 45nm, quad-core Nehalem design with an
onboard triple-channel memory controller, (the return of the son of)
Hypterthreading, Turbo mode (basically, internal automatic overclocking on
demand), a fast QPI interface between the CPU and the North Bridge, and a large
L3 cache. As such it only supports triple-channel DDR3 RAM and requires the
Intel X58 chip set, and as such it is a rather expensive option, mostly because
of the DDR3 RAM.

Also, due to the triple channel RAM controller, to get optimal performance on
the Core i7 you have to install memory in threes while you only needed memory in
pairs for the older Core 2 CPUs. You CAN run an i7 Bloomfield with a dual memory
configuration (e.g., 4x2GB), but performance will not be optimal. Due to this
you will see Bloomfield motherboards offering 6 slots instead of 4, for a
maximum of 24GB (6x4GB).

(Note: For the heavy-duty workstation crowd, the Xeon 35xx series CPU has the
same Nehalem microarchitecture, except that it supports ECC RAM and a dual-CPU
configuration; the Core i7 CPU does not.)

The brand new "Lynnfield" is a slightly lower-rent option. It is still a Nehalem
microarchitecture, but with some tweaks to the design to differentiate it with
its older bigger brother:

- Still a 45nm quad-core design;
- Removed one of the channels in the onboard memory controller, so it supports
DDR3 memory in dual-channel RAM configurations;
- No QPI interface between the CPU and the North Bridge (instead it uses slower
connection called DMI).
- Integrated PCI Express 2.0 on the CPU (not as useful as you may think)
- Hyperthreading enabled on only "some" Lynnfield offerings)
- Better fine-tuning of Turbo Mode overclocking.
- New docket design (the LGA 1156) which requires a new chipset (the Intel P55)

What's bad is that the Lynnfield goes by both the "i5" and "i7" moniker.
Basically, an i5 Lynnfield does not support Hyperthreading, while the i7
Lynnfield does. You have to pay close attention to the CPU number to designate
between the two variants (prices are from Newegg):

Lynnfield:
Core i5-750 (2.66 Ghz) ($ 210)
Core i7-860 (2.8 Ghz) ($ 300)
Core i7-870 (2.93 Ghz) ($ 580)

Bloomfield:
Core i7-920 (2.66 Ghz) ($ 280)
Core i7-940 (2.93 Ghz) ($ n/a) Note: Discontinued
Core i7-950 (3.06 Ghz) ($ 570)
Core i7-975 (3.33 Ghz) ($1,000)

As with all Intel CPUs, once you hit the low 3-Ghz range the price goes through
the roof.

Overall I think they are all great CPUs, but in particular the Core i5-750
Lynnfield is actually a really good value:
http://www.pcper.com/article.php?aid=776&type=expert&pid=15

Even as the runt of the litter, it's still way faster than a Core 2 Quad CPUs
like the Q8400 (also at 2.66Ghz) which is at the same price point.

In rendering, the i7-870 Lynnfield is benchmarking almost as fast as the i-975
but is half the price. I do not have figured on how well the i-950 fits in the
sceme of things, but I bet the differences are close to none.

The Lynnfields are also less power hungry than the Bloomfields.

=====================================================================================

Conclusion:

It seems to me that you can split the decision to two processors, the Lynnfield
i7-870 and the Bloomfield i7-950. The difference is in the software you use.

For what you do, I think a Lynnfield i7 based CPU is really good, using a P55
motherboard with 8GB (4x2GB) DDR3 RAM. I would opt for the i7-870.

For someone who uses Revit, 3ds Max, and Photoshop extensively, RAM is key. In
that case I would opt for a Bloomfield i7-950 CPU. Why? While it's the same or
only slightly faster than the same-priced i7-870, it has a triple-channel RAM
controller, meaning it requires a X58 motherboard with 6 slots, meaning you can
install more RAM than a Lynnfield/P55 board (12GB rather than 8GB for a
mainstream configuration).

Matt
matt@stachoni.com
*Matt Stachoni
Message 5 of 16 (2,113 Views)

Re: Intel Core i5 and i7 CPUs

09-09-2009 05:49 PM in reply to: *Dean Saadallah
Hah, just found this:
http://techreport.com/articles.x/17545/1

It seems the i7-850 compares EXTREMELY well against - even beating in some cases
- the I7-950. It's really due to the improvements in the Turbo Mode in the
Lynnfield.

And this was testing an i7-850 with only 4GB of RAM against an i7-950 with 6GB
of RAM. That's _really_ impressive. Factor in the less power draw on Lynnfield,
and it's not really a contest.

So, I'd now say unless you reaaalllly needed over 8GB of RAM, the Lynnfield
i7-850 is the one to get, which should really cover about 80% of all mainstream
CAD users.

Matt
matt@stachoni.com
*Dean Saadallah
Message 6 of 16 (2,113 Views)

Re: Intel Core i5 and i7 CPUs

09-10-2009 05:32 AM in reply to: *Dean Saadallah
Thank you kind Sir, great details.

--
Dean Saadallah
http://LTisACAD.blogspot.com
--
*John Mayo
Message 7 of 16 (2,113 Views)

Re: Intel Core i5 and i7 CPUs

09-10-2009 07:24 AM in reply to: *Dean Saadallah
Good stuff Matt, Thanks.

--
John Mayo, PE

Core i7 920 6GB DDR3
Radeon 4870HD 1 GB
Vista64
Member
RRBlum
Posts: 4
Registered: ‎02-17-2003
Message 8 of 16 (2,113 Views)

Re: Intel Core i5 and i7 CPUs

09-11-2009 07:50 AM in reply to: *Dean Saadallah
Matt:

I'm confused. I can't find reference to a core i7-850 processor. Do you mean i5-750 or i7-870?

It looks like either is impressive, but it seems to me that the i5-750 (with Win 7) is the best value for CAD users. Personlly, I'm waiting to see how the chipset/motherboard market sorts itself out before building a new Win 7 machine.

R. Blum
*Matt Stachoni
Message 9 of 16 (2,113 Views)

Re: Intel Core i5 and i7 CPUs

09-11-2009 04:50 PM in reply to: *Dean Saadallah
On Fri, 11 Sep 2009 14:50:46 +0000, RRBlum <> wrote:

>Matt:
>
>I'm confused. I can't find reference to a core i7-850 processor. Do you mean i5-750 or i7-870?

Arg, sorry, the i7-870.

>It looks like either is impressive, but it seems to me that the i5-750 (with Win 7) is the best value for CAD users. Personlly, I'm waiting to see how the chipset/motherboard market sorts itself out before building a new Win 7 machine.

Probably. For most benchmarks it performs about on par with the i7-920 (both are
very similar - 2.66GHz, 8MB cache and the same price). The fact that it doesn't
have hyperthreading is tempered with the fact that it already has 4 cores
anyway, and most software isn't multi-threaded well enough to really take
advantage of it. In single-threaded apps, the 850 performs better due to its
internal TurboBoost advantages. In multithreaded apps the 920 passes it, and in
rendering times by a wide margin.

Matt
matt@stachoni.com
Active Contributor
Roobuls
Posts: 30
Registered: ‎09-15-2009
Message 10 of 16 (2,113 Views)

Re: Intel Core i5 and i7 CPUs

10-16-2009 11:44 PM in reply to: *Dean Saadallah
I thought the i7 Lynnfield DOES have multithreading ?
> =======================

>

> Probably. For most benchmarks it performs about on par with the i7-920 (both are very similar - 2.66GHz, 8MB cache and the same price). The fact that it doesn't have hyperthreading......

>
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