Best bang for the buck for stingy renderers?

[Ecuadorian]

I've been putting off the upgrade to a Core i7 920 because of the high cost of the motherboards. I hate it when I pay too much for something that is obsolete in no time (especially Intel/Foxconn motherboards, which have failed me twice), so I always try to find the best bang for the buck at a given time instead of looking for the bleeding edge... which often makes you bleed. I'm still bleeding from past expensive purchases.

Today I received an e-mail from my parts provider telling me that the Core i5 750 and Core i7 860 have just arrived. They still have no pricing for them, but from U.S. prices it seems that a i5 750 and the corresponding motherboard should be cheaper than a i7 920 and corresponding part. I also love the fact that it consumes less power, which translates to less $$ in my monthly electricity bill, as I also use heavy Air Conditioning in the hot season and hotter CPU = More A/C. After some Google searches, I found this battery of rendering tests:
http://www.anandtech.com/cpuchipsets/sh ... =3634&p=13

In the 3dsMAX 8 rendering test the cheaper i5 750 has 84% the performance of the i7 920.
In the Blender render test the i5 750 has 91% the performance of its bigger brother.
In the Cinema 4D test the i5 has 87% the performance...

So it sounds like a sweet deal. The performance is in the same order (unlike my current Core 2 Duo which has 27% the performance of the i7 920 in MAX tests), it is cheaper, uses a cheaper motherboard, does not require you to install three memory modules at once (only two), and consumes less power, which translates to less power expense plus less heat and less A/C = even less power expenses, and after taking a peek at Intel's roadmap it seems most future processors will use the same socket. It has no Hyper Threading, but, as I proved once over the SCF, more logical cores don't always translate to better performance. In some cases, further dividing of a task can actually harm performance because of the increased overhead. As long as there are 4 physical cores giving me 100%, I think I'll be happy.

Has anyone here grabbed both a i7 920 and a i5 750 and tested both with KT or Twilight?

[Fletch]

all I can say is:
1 - do an actual calculation of real money/power savings per year between the two... my guess is the diff. in power consumption will equal a pizza in a year. hardly something to pin the decision on.
2- the price diff. as near as I can tell is about $100US, for 87-90% of the performance... I don't know what you get paid for your renderings, but I'd rather have the 100% performance. If you overclock, maybe you can get even better.

maybe including Mobo, and RAM, etc. it will be much cheaper, but I'd certainly do more calcs before cutting myself to 4 cores... that's my 2 cents.

[Ecuadorian]

The Core i7 920 is tempting... indeed the price difference is not that much in the great scheme of things...

But I still love the bragging rights of building the best bang-for-your-buck system. I'm a deal hunter. I waited patiently until the Mitsubishi HC1500 projector came down to 60% its original price to take the plunge, after having done the same thing with the InFocus IN72 the year before. I ordered most cables and other pieces for my projector online and waited for them patiently to come from the U.S. instead of spending more at the local Radio Shack.

I guess I'll grab the i5, pocket the difference and order that pizza you mentioned... . No, seriously, after remembering how my brother spent $2,500 on a Pentium-I IBM Aptiva H76 back in the day and how he refused to get rid of it when it became obsolete (we still have it), I've become even more resolved to be cheap.

I guess I forgot to tell you that the Core i5 750 is faster than the Core i7 920 in games and applications which don't use all cores thanks to its turbo mode. Actually, its overall system score is equal or higher (varies by source) than that of the 920. You know, there's more to life than working.

[Solo]

Miguel, think about it carefully, the i7 is the better machine for rendering, and it can be upgraded next year or the year after to 12 threads. IMO you would be penny wise and pound foolish not to spend the difference and get the better machine. I see you wrestling yourself with this decision, trying to convince yourself when you know the right decision. If you do get an i7, try get an Asus deluxe mobo.

[Fletch]

...there's more to life than working.

indeed.... there's always spearfishing... but my computer doesn't do well underwater.

[notareal]

I think you should look how much more you will earn with 20-25% increased productivity - go with i7 not i5.

[Ecuadorian]

Still have around 2-3 weeks to make up my mind, that's when I'll have the money for the upgrade. And what about the Core i7 860? It is also Lynnfield, and thus uses dual-channel memory and the new LGA socket, is on par with the i7 920 on multi-threaded apps but beats it on single-threaded ones. I know the old socket will allow me to upgrade to a 6-core, but I'm still trying to figure out if the new socket isn't better in the long run, as I read in Anandtech the new Lynnfields were designed in collaboration with Microsoft with special features for Windows 7. The list of future processors showed most will use the new socket. I need an Intel insider...

[Solo]

Miguel, the way I see it:

The i5 vs i7 is simple , the i5 is a mainstream setup and the i7 are now more enthusiast. The i5 does not have multi-threading and cannot be clocked at i7 speeds, so for apps that take advantage of multi threading like most render software it's a no brainer that the i7 will trump every time.
The i5 will be a great performer at a budget price, it was designed with gamers in mind that need power on a budget, and the i5 is designed with laptops in mind.
If you can get an i7 "bloomfield" 1366 socket with a x58 mobo IMO you would have the better machine for rendering, even against the "Lynnfield" 1156 P55, the Bloomfield is faster.
Another plus is the Ram, triple vs dual. Then you have the new chips on the horizon that will work on the X58, so upgrading to 6 core/12 threads will be at only the cost of the chip-set.
Again, this is a personal choice, but if performance is what you want then go for an i7 as you can squeeze much more juice out of it, go for the 860, it overclocks very well and it will support the new chips, triple channel, etc.

[notareal]

I see i7 860 and 920 equally good options. With 860 you would most likelly be able to build a bit faster system (when overclocked) in a bit lower cost, but 920 do have a known (at the moment) upgrade path to 6 core and motherboards with solid bios. Both 920 and 860 will benefit of use of Windows 7, but 860 do have better turboboost. But keep in mind, that when you OC, you generally need to disable turboboost. i7 920 systems are know to OC near 4 GHz, 860 looks good in that field and what I seen in different forums is better to OC, but need a good motherboard for that (Asus boards for 1156 socket seems not that good for OC, MSI might be better option, take a look on http://www.hardocp.com). If looking only at the moment I would go to i7 860 even, if I would not OC. Speculating of what might come in future, do not generally help, but my bet is that there will be i9 or equal for 1156 socket too - but also I expect a 8 core for 1366 socket (iX... or something) and after that 1366 socket is history.

[Ecuadorian]

and after that 1366 socket is history.

That seems to be the case. Decisions, decisions...

Same article in Anandtech painted the Core i7 870 (Lynnfield, LGA 1156) as pure awesomeness, so another option is buy a Core i5 750 now with two memory modules and upgrade to a 870 (or whatever is available) later with two more memory modules, as it's dual-channel and I hope to find a mobo with 4 slots. On the Bloomfield side of things, the only 1336 motherboard in my provider's pricelist is the Intel DX58SO, but it has four memory slots, which is not the optimal memory upgrade path when talking about tri-channel mem... you should have 6 slots for that: install three today, three more later.

I never overclock anything, the use I give to the parts (occasional 5-minute 30fps walk-throughs) is already stressful enough for them and I end up having to replace broken parts (hard drive, mobo, power source, optical drive) before the next processor upgrade.

Thank you for all your insight, I'll tell you how it turns out. Now I have some testing to do .