Socket concerns: i5 750 vs. i7 920 vs. Phenom II X4 965

[src1425]

It's been 5 years since I built my system (Athlon 64 X2 4800+ on a DFI LANPARTY UT nF4 Ultra-D) , so I've really had to catch up on the current technology. My system is for moderate gaming, occasional video editing, and general productivity. My top priorities are longevity > upgradability > performance > value.

I was initially looking at the i5 750, but it seems like LGA 1156 might not be around terribly long. And for the cost of an i5 750 with a P55 USB 3/SATA III board, I can get an i7 920 with with an inexpensive X58 board. But I don't know how long LGA 1366 is supposed to be around. Phenom II X4 965 seems to be only a small step down in terms of performance, but is the potential longevity of AM3 worth it?

The more I look into this the less certain I am, so any guidance would be much appreciated.

 

[Silmarunya]

Well, P55 certainly offers hugely limited upgrade paths, and that was why I've been in doubt about buying it for so long. However, I went ahead using the following logic:

- X58 offers good upgrade paths, but the price premium is huge and the performance difference non-existent (at stock speeds, 1156 CPU's outperform 1356's and overclocked the i5-750 can keep up very well too). This one is out easily, unless you're obsessed about having Crossfire or SLI

- AM3 offers amazing upgrade paths, but their CPU's are outperformed by the P55 ones and the graphics limitations are the same as those of P55.

- P55 is good enough for most crossfire setups, offers better performance than AM3 at a relatively modest premium and far better value for money than X58. The limited upgrade paths are a problem.

But how long do you intend to keep this new PC? Another 5 years? Well, an i5-750 will still be going strong in 5 years, especially if overclocked a bit. Remember that gaming is GPU bound and not CPU bound. If anything will need to be upgraded, it will be the graphics card and that's possible no matter what platform you pick. And who knows what's still on the horizon? As Intel's mid-end platform, they might still launch new mid end CPU's. And mid end CPU's in a few years time will be better than today's upper middle class CPU's like the i5. And if you must upgrade for some reason, an i7-870 will be dirt cheap in a few years, offering a decent upgrade too.

If you must have excellent upgrade paths, go AM3. But if you're fine with starting again from scratch in 5 years, like you're doing now, you won't need a CPU upgrade anyway if you're not afraid to overclock.

 

[Lmeow]

Well, AM3 will only officially support Phenom II X6, which are speculated to perform the same or better than Core i7s in multi-threaded applications, but in single core applications, the i7 will outperform the Phenom II X6. It may or may not support AMD Bulldozer, but I wouldn't think so because it'd be a complete new architecture. LGA 1156 isn't dead, but I don't many new CPUs will come out for it. I'd say in terms of upgradability, Core i7 900s would be a better choice, and will last you for quite a while - graphics cards are 'more' upgradeable with Core i7 900s because of the X58 chipset, and you'll be able to stick one or two, possibly even three graphics cards in the same board later on. If you can afford it, and only intend to use one or two graphic cards, I'd go for an i7 860 + ASUS P7P55D-E Pro combo.

 

[src1425]

Well, that certainly gives me something to think about. Thank you both for your answers. Yes, I'd like to get about 5 years out of the MB and memory, with a possible CPU upgrade in 3 years or so if necessary.

In case it makes any difference, this is more of a rebuild than a brand new system. I only use 1 GPU, currently a Radeon HD 4850, which I'll upgrade towards the end of the year. Will also reuse my case, hard drives, and PSU, as I'd rather upgrade incrementally.

 

[Raidur]

All 3 will have a future upgrade path. AM3 gets BullDozer and 1366/1156 get Sandy Bridge.

None of these chipsets are dieing any time soon.

 

[flaminggerbil]

For gaming you'll find no difference between an i5 750 and an i7 920, the same with dual / tripple channel ram.

The only time you'll really want to spend the extra for 1366 is if you're planning on running two top end cards in sli, but they'd have to be along the lines of 480's to have any significant difference (even then I'm not completely sure).

Also as people have said, both 1156 and 1366 have a long way to go, not that there's much point in buying based on futureproofing.

 

[smithereen]

I'd wait until Thuban comes out in about a month, it may be better value than i5/i7. Wait for the reviews, of course, but it should be good, and I can't see it or an i7 being obsolete in the next four years.

BTW, what Silmarunya said about AM3 having "the same graphical limitations as p55" isn't quite true, you can get 16X-16X, 8X-8X-8X-8X Crossfire or 16X-8X-8X SLi on an AM3 board. Of course, he was probably talking about having to chose either SLi or crossfire when buying the board.

 

[Raidur]

For gaming i7/i5 are going to smack around Thuban, especially if you overclock.

Also, about the pcie bandwidth, give this a read.

http://www.techpowerup.com/reviews/AMD/HD_5870_PCI-Express_Scaling/25.html

As you can see a 5870 loses no more than 5% on a 4x slot. Meaning even a 5970 won't be bottlenecked by an 8x slot by more than 5%. (I'm guessing its going to take dual GPU 6series ATI cards to get a significant hit from the bandwidth limit of 8x)

 

[Silmarunya]

For gaming i7/i5 are going to smack around Thuban, especially if you overclock.

Also, about the pcie bandwidth, give this a read.

http://www.techpowerup.com/reviews/AMD/HD_5870_PCI-Express_Scaling/25.html

As you can see a 5870 loses no more than 5% on a 4x slot. Meaning even a 5970 won't be bottlenecked by an 8x slot by more than 5%. (I'm guessing its going to take dual GPU 6series ATI cards to get a significant hit from the bandwidth limit of 8x)

If that conclusion is valid, it's a huge eye-opener. That x8 was equal to x16 even in high end graphics configurations was obvious, but x4 not bottlenecking a rather high end card like the 5870 is a HUGE surprise to me...

I had accepted that's I'd never be getting a second graphics card on my Asus P7P55D-E, but if it barely bottlenecks the 5870, another 5850 should run smoothly on the lowly x4 slot. However, so many sites keep claiming the gap is a LOT wider, so I'm still having my doubts.

 

[Lmeow]

In a single configuration, 4x PCI-e bandwidth will not bottleneck the HD 5870 for example, but in CrossFireX, 8x/8x/4x definitely shows signs of severe bottlenecking:

http://www.tomshardware.co.uk/p55-pci-express-scaling,review-31780-7.html

AFAIK, I thought all ASUS P7P55D-E boards had 8x/8x bandwidth. I could be wrong, though.

 

[Silmarunya]

In a single configuration, 4x PCI-e bandwidth will not bottleneck the HD 5870 for example, but in CrossFireX, 8x/8x/4x definitely shows signs of severe bottlenecking:

http://www.tomshardware.co.uk/p55-pci-express-scaling,review-31780-7.html

AFAIK, I thought all ASUS P7P55D-E boards had 8x/8x bandwidth. I could be wrong, though.

According to the Asus website, the second slot runs in x4-mode... And yes, it bottlenecks in crossfire, which sucks. But most tests I could find are done with a 5870. Would the gap be as huge for a 5850?

 

[src1425]

Best answer selected by src1425.

 

[src1425]

I'd wait until Thuban comes out in about a month, it may be better value than i5/i7. Wait for the reviews, of course, but it should be good, and I can't see it or an i7 being obsolete in the next four years.

Fortunately, I'm not looking to order for a month or so. If Thuban provides i7-equivalent performance for 2/3 price, I'd be happy to go that route. Of course, if it drives down i5 and i7 prices, I probably won't lose either way!

Thanks all for the helpful comments.