Looks like the GTX660Ti will be getting released next week and it looks like it will be using the same GPU as the GTX670 (GK104 with 1344 CUDA cores) but with a 192-bit memory bus instead of the 256-bit memory bus used in the 670. Also looks like the TDP is 20W lower than the 670

Will the lower memory bus width have much of an impact on GPUGRID performance?

Thinking of treating myself to a new card, but undecided between the 670 or the 660Ti.

It's really a case of wait and see. Even then, without standard output details it will be very difficult to work out the best cards and best setup.
I suspect a 192bit bus won't be a huge loss, especially on a PCIE3 setup. I don't know the details of these cards yet, just the speculation. Other rumors suggested 256bit for the Ti and 192 for the 660... Recent tasks tend not to use the CPU as much, so if this continues perhaps the bus won't matter as much. If the TDP is 20 or 25W lower then that might be an indication of relative performance. Performance per price and per running cost is still unknown, until someone does a real test and publishes. This should happen within the next two weeks.

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16th August is rumoured as being release day so reviews should start coming out then.

Well, the good thing is I won't need to upgrade to a bigger PSU as dual GTX670 would be OK with my current one.

The GTX570 seem to have dropped to bargain prices to get rid of stock prior to the 660 release, but the higher running costs are putting me off and I'd have to invest in a new PSU to run dual 570's.

Release day has come around and prices in the UK seem to be from around the £245 up to about £320.

At the moment I'm edging towards a GTX670....

Upgrade is planned for the end of the month... with a bit of luck someone might try one GPUGRID before I place my order.

I have one on the way and should be able to post some results next week.
For a start I'll be plugging it in to the same system as a GTX670 where both will be running at PCIE2 X8 so we can get a decent baseline.

- PCIE3 systems are kind of hit and miss right now as while they may be electrically capable most are not running at PCIE3 without a reg hack that may or may not work on a model by model basis.

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Thanks - Steve

Just checked one UK supplier and I can get them from £235 to £260. I expect prices might initially rise and after a month or so, fall (unless AMD have something to say about it). I'm seeing the reference 928MHz up to 1033MHz (manufacturer specific/bespoke versions), but there is no official reference NVidia model. This is good as it means there is a good range of card specs just within the GTX660Ti and GTX670/680 models.

For single card systems I suggest people get a dual fan version, and the bigger the blades the better.

Review at Anandtech by Ryan Smyth

The question as far as here is concerned, is how much was lost in the drop from 32 to 24 ROP's and the drop from 256 to 192bit bus width (which are linked); what does GPUGrid do on the ROP's. For gamers the 192bit bandwidth might be an issue for a single card setup playing some games, but 2GB avoids memory capacity issues (assuming the drivers can adequately accommodate the asymmetry). The competition is HD 7870 to 7950.
The gain is -20W TDP (but around 7W saving in reality), price and competition.
I don't know if these will work straight out of the box, but assuming they do (driver dependent) I can't see them being any worse than 20% less than a reference GTX670. Most likely they will almost be on par (within 5% making the GTX660Ti better value for money). Best case scenario a higher clocked GTX660Ti outperforms a reference GTX670 (for here), and stays within the reference TDP (cheaper, faster, cheaper to run).

BTW. Based on performance (games etc) I consider these cards high end, not mid range. The idea is somewhat akin to the GTX560Ti448.

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Just checked one UK supplier and I can get them from £235 to £260.

Sorry to hear you guys have to pay that much ... I got mine for USD $299 + shipping ... (total £196). It has shipped and I should have it in hand on Monday. The upshot is I have Monday off from work so I should be able to get it up and running right away! Of course the installation schedule is subject to change without notice as my wife may have plans for me that I don't know about yet :-O

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Thanks - Steve

Hence the phrase, 'rip-off Britain'.

Have plans back at her, or better still, get in there first :))

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Just checked one UK supplier and I can get them from £235 to £260.

Sorry to hear you guys have to pay that much ... I got mine for USD $299 + shipping ... (total £196). It has shipped and I should have it in hand on Monday. The upshot is I have Monday off from work so I should be able to get it up and running right away! Of course the installation schedule is subject to change without notice as my wife may have plans for me that I don't know about yet :-O

So which make have you ordered?

Will be interesting to see how it compares with a 670 in the same system

GIGABYTE GV-N66TWF2-2GD GeForce GTX 660 Ti
Core clock is factory OC'd from stock 915 to 941 but I'll likely go higher.

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Thanks - Steve

Well, after umming and arring for nearly a week I have just pressed the button on an EVGA GTX670, due for delivery tomoorow :-)

Haven't completely ruled out a GTX660Ti, I might get one later this year to replace my GTX550Ti

GIGABYTE GV-N66TWF2-2GD GeForce GTX 660 Ti
Core clock is factory OC'd from stock 915 to 941 but I'll likely go higher.

After 1 NATE WU it appears to take slighlty less time that a GTX480 but at roughly half the electricity usage.

A couple of notes of comaprison to a GTX670 ... the power usage % is mid to high 90s where on the 670 it runs in the 70s. Also, the MEM % usage is also a bit higher in the mid 40s (no surprise with the 192 bus) compared to mid 20s.

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Thanks - Steve

The ROPs are the "raster output units". Since we're not actualy rendering anything at GPU-Grid (just crunching numbers), these don't matter at all. The reduced memory bandwidth will have a slight effect, but in the past GPU-Grid hasn't been particularly memory bandwidth starved. This is reflected by Steves measurements: the memory controller is used at ~40% of its capability on the GTX660Ti.

For GPU-Grid (and most other GP-GPU apps) this card should provide significiantly better bang-for-the-buck than a GTX670.

MrS

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Sorry to hear you guys have to pay that much ... I got mine for USD $299 + shipping ... (total £196).

The base price is the same. If we paid 17.5 % VAT our cost would be similar.

(Expat Brit for a reason)

Had my 660Ti running for a week, exclusively for GPUgrid.
All I can say is, fantastic.

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Guys:

What is the verdict on this card? From the specs, it looks like the 660Ti would be the best GPU for the money. Does the performance approach that of the GTX670? Why pay the extra for the GTX 670? It only has about 18% more shaders.

I am looking to upgrade my GTX 570s so I need some guidance.

Thank you

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Thx - Paul

Note: Please don't use driver version 295 or 296! Recommended versions are 266 - 285.

It's got exactly as much runchng power as the GTX670 (same shaders, same clock). GPU-Grid needs a little memory bandwidth, but usually not as much that it would hold a card back. So GTX660Ti performance should be very close to a GTX670 here and hence be an excellent buy.

I can't give you exact numbers, though, as mine crunches only POEM.

MrS

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In the next month or so I'll be making some upgrades to my systems and 1 or possibly 2 GTX660TI's will be acquired I'm tempted to upgrade one of my systems to a Asus Crosshair motherboard to utlilse the extra slots.....

Have to wait and see what bonus I'll be getting before Xmas before I make my mind up and then plan deliveries so that the Mrs is at work!!!

There is no doubt that the GTX660Ti is great value for money when it comes to crunching here; it costs a lot less than the GTX670 and the running costs are low compared to previous generations.

However, there are many different task types, and with some types, the GTX670 is significantly better. For other types the difference may be less than 3%, making the GTX660Ti a more favourable card due to the substantially reduced purchase outlay.

Unfortunately with so many task types it's too difficult to make a solid percentage comparison of the different cards performances.
System variation is also increasing, so Operating System (Linux, XP, Vista/W7/W8/2003R2/2008R2), CPU, RAM, PCIE, and possibly hard drive performances may now influence the overall crunching performance to an increased extent.

Along with GPU memory bandwidth variations, considerations include non-standard cards (performance can vary by up to ~16%), the lack of Boinc task reporting (to actually show the cards frequencies), and variation in performance between GPU generations for different task types (which can be very large). So the construction of a cross-generation table of performance would be very difficult and quite transient; subject to changes in task types. The construction of a reliable performance per Watt table would be even more difficult, and such tables wouldn't address other considerations such as reliability, warranty, heat or noise.

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However, there are many different task types, and with some types, the GTX670 is significantly better.

Any hard data?

MrS

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