Seven GeForce GTX 660 Ti Cards: Exploring Memory Bandwidth

Features
By Igor Wallossek
published

Seven GeForce GTX 660 Tis landed in our lab. Today, we're benchmarking them, measuring their noise and temperatures, and conducting a more in-depth analysis of the impact a 192-bit memory interface has on performance. The results are enlightening!

Power Consumption

Below each company's highest-end graphics cards, most offerings perform pretty similarly when it comes to power consumption. Nvidia's GeForce GTX 660 Ti really doesn’t have an advantage compared to the faster competition, except for the Radeon HD 7950’s high power consumption during Blu-ray playback.

Looking at the different interpretations of the GeForce GTX 660 Ti, Zotac's GeForce GTX 660 Ti AMP! Edition stands out with high GPU and memory clock speeds, and the Galaxy GeForce GTX 660 Ti GC 3 GB stands out for its extra memory. But neither exhibits dramatically different power use.

The consumption of two passively-cooler Radeon HD 7750s in CrossFire, operating at 1920x1080 with 8x MSAA is 98 W (102 W in Crysis 2). This is about 20 W less than Nvidia's GeForce GTX 660 Ti’s 118 W measurement (124 W in Crysis 2), and the GeForce was slower than the 7750s. The efficiency of Nvidia's GeForce GTX 660 Ti tanks once it's limited by memory bandwidth. Power consumption doesn't drop with frame rate. As a result, AMD's cards are as or more efficient at medium frame rates.

Real Clock Speeds under Full Load

We used the following graph earlier in this piece when were trying to explain why the different GeForce GTX 660 Tis didn't line up in the order we were expecting in 3DMark 11. Let’s take a closer look at where each card's thermal ceiling seems to be, and just how much GPU Boost acceleration the cards really get.

This is also interesting from a power consumption point of view. Our Asus GTX 660Ti DirectCU II simply stays at 915 MHz, which paints its thermal and acoustic performance into a different light since it's a lot easier to cool a card running 250 MHz slower.

MSI's N660 Ti PE 2GD5/OC shows particularly well. Zotac's GeForce GTX 660 Ti AMP! Edition, on the other hand, doesn't benefit from GPU Boost at all. Generally speaking, the cards on longer PCBs with an additional power phase are enjoying higher boosted clock rates than the ones using Nvidia's reference GeForce GTX 670 board.

Power Consumption Benchmarks in Different Scenarios

Igor Wallossek
79 Comments Comment from the forums
  • scotthulbs
    I'd Like to know which 2GB model 660ti you used in this comparison? I would like to see how if perhaps the Zotac memory overclock has much of an effect on performance. If you used the Zotac in this comparison that may very well be the reason it outperforms the 3GB Galaxy card? Maybe run this same test overclocking the memory, it seems as though the 660ti with its memory overclocked can nearly reach GTX670 Bandwidth. I'd like to see how much that helps overcome the narrow bus.
    Reply
  • mayankleoboy1
    The problem with wider memory interface is that it exponentially increases the chip's die-size. Hence, cost per wafer and power consumption will increase a lot.

    IMO both AMD and Nvidia should use the XDR2 memory in the next series of cards. That would give the same bandwidth at half the interface size.
    Reply
  • iknowhowtofixitThis review reinforces what I have been saying for weeks. The GTX 660Ti is overpriced at $300. Since you can easily find a HD7950 for $300 or less after rebates, it makes the 660TI irrelevant. To me, the 660Ti needs to be $60-$75 cheaper before it can achieve bang for the buck status.it is because of the 660ti that the 7950 prices dropped to $300 or less with MIR: so tell me how irrelevant they are now?
    Reply
  • ahrensy
    For the Batman Arkham City tests on the 670 and 660ti, was the PhysX setting set to Off, Low or High?
    Reply
  • EzioAs
    9537131 said:
    it is because of the 660ti that the 7950 prices dropped to $300 or less with MIR: so tell me how irrelevant they are now?

    The 7950 has been our for months now compared to the 660ti and the price drop happens before the release of the 660ti. Nvidia should really have predicted that the 7950 prices should come down even more so it makes almost no sense that they release the 660ti at $300.

    The 7870 performs just slightly slower compared to the 660ti but beats it once you crank up the AA really high and it costs $50 less. On the other hand the 7950 is overall faster than the 660ti and even surpass the the $60+ 670 once you crank the AA really high as well. For the 660ti to sell, Nvidia should really lower it to $260 imo.....or they could just rely on fanboys
    Reply
  • 9537133 said:
    The 7950 has been our for months now compared to the 660ti and the price drop happens before the release of the 660ti.

    AMD cuts HD 7000 series price even furtherTuesday, 21 August 2012 08:57 (after the 660ti release)
    AMD has already dropped the HD 7970 from US $479 to US $429, HD 7950 from US $399 to US $349 and the HD 7870 down from US $349 to US $299. The new price cut skips the HD 7970 graphics card but includes the HD 7950, HD 7870 as well as the 1 and 2GB versions of the HD 7850.

    The most important is probably the price cut for the 3GB HD 7950 which battles it out with Nvidia's recently released GTX 660 Ti. The HD 7950 3GB is, according to the report, will receive a US $30 price cut placing it at US $320. The HD 7870 2GB graphics card got another US $50 price cut pushing it down to US $250 which probably makes it one of the most interesting mid-range graphics cards on the market.

    cheers! :)
    Reply
  • FormatC
    9537132 said:
    For the Batman Arkham City tests on the 670 and 660ti, was the PhysX setting set to Off, Low or High?
    PhysX was off, because it affects the overall performance. PhysX is dead - ok, not quite, but almost ;)
    Reply
  • EzioAs
    9537134 said:
    AMD cuts HD 7000 series price even furtherTuesday, 21 August 2012 08:57 (after the 660ti release)
    AMD has already dropped the HD 7970 from US $479 to US $429, HD 7950 from US $399 to US $349 and the HD 7870 down from US $349 to US $299. The new price cut skips the HD 7970 graphics card but includes the HD 7950, HD 7870 as well as the 1 and 2GB versions of the HD 7850.

    The most important is probably the price cut for the 3GB HD 7950 which battles it out with Nvidia's recently released GTX 660 Ti. The HD 7950 3GB is, according to the report, will receive a US $30 price cut placing it at US $320. The HD 7870 2GB graphics card got another US $50 price cut pushing it down to US $250 which probably makes it one of the most interesting mid-range graphics cards on the market.

    cheers! :)

    If you check the price of the 7950s before this news at most online retailer (Newegg, NCIX), you'll know that the price drop happens already although the official news from AMD was a couple of weeks later
    Reply
  • 9537136 said:
    If you check the price of the 7950s before this news at most online retailer (Newegg, NCIX), you'll know that the price drop happens already although the official news from AMD was a couple of weeks later
    now you are talking complete nonsense unless you do not understand there were two price drops and the latter of which is because of the 660ti; as the article stated.so you want to see pricing history . . :)
    Sapphire Radeon HD 7950 3GB Video Card
    now how much sense does it make to drop prices and not tell anyone?
    :pfff:
    Reply
  • Cryio
    Tom's, I want to make a request article. Where should I post it? :D
    Reply