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Radeon HD 5770, Radeon HD 4890, And GeForce GTX 275 Overclocked

MSI N275GTX Lightning: Fully Overclocked

Now it’s time for our own little warning: overclocking can damage your hardware and void your warranty. However, there are some good rules of thumb to help you prevent frying your graphics board. Usually, you can increase a card’s default clock speed by another five to ten percent. Don’t jump to the highest setting immediately. Instead, increase the frequency in increments of 5 or 10 MHz and test stability. Also, don’t try to change all settings at once. Find the highest stable frequency for the GPU, then move on to the shader, followed by the memory.

We recommend using a graphically-demanding game that puts a lot of strain on the GPU to test your settings. Anything with the Unreal 3 engine should work well (Ed.: here at the Tom's Hardware US office, we like to use FurMark for stress testing). Select a high resolution (ideally 1920x1200), turn off anti-aliasing and enable anisotropic filtering. If the game freezes, that usually means the GPU frequency is too high, while visual artifacts and rendering errors tend to mean the memory can’t cope with the selected clock speed. Lower the speeds immediately in either case. Finally, if you get a DirectX error, chances are your shader clock was set too optimistically.

MSI’s factory overclocked settings work flawlessly. However, we encountered several problems when we attempted to overclock the card. Since MSI’s own OC tool wouldn’t let us adjust the shader clock, we used eVGA’s Precision tool instead, with a goal to achieve the highest clock speed possible that didn’t require a voltage tweak. That turned out to be more difficult than it sounds, since our combination of Windows Vista, Forceware 191.07, and MSI’s Lightning Afterburner software turned out to be a little, let’s say, touchy. If the overclocked settings don’t work, Windows Vista kills and restarts the graphics driver, after which the card only runs at half speed. The only way to get out of this 400 MHz mode is to reboot the system.

After half a day of experimenting with various clock speed combinations, we found 720/1,600/1,200 MHz (GPU/shader/memory) to be the safest, most stable settings. Interestingly, the 1,200 MHz memory speed corresponds to the highest setting in MSI’s Lightning tool.

In order to increase the GPU speed further, we had to perform a little ritual in a specific order. Start MSI’s OC tool, raise the voltage, then launch Precision to overwrite MSI’s clock speeds. This took several more hours, partly because MSI’s utility proved to be very dominant. Switching to another performance preset or using one of the Lightning utility’s frequency sliders immediately overwrites any settings selected through Precision. Then, if you choose a clock speed that is too high, the system will freeze or the graphics driver will reset itself, restarting in 400 MHz mode. Either way, you’re forced to reboot the system.

Raising the voltage a little from 1.0665 to 1.0790 V allowed us to push the GPU as far as 770 MHz. Remember, Nvidia’s reference speed is 633 MHz, while the GTX 275 Lightning has a stock clock of 700 MHz. This setting wasn’t without its problems, though, as the system would become unstable under load. Additionally, 1,600 MHz was no longer a viable option for the shader, and we had to reduce the memory frequency to 1,170 MHz as well. After lots of trial and error, we ended up at 770/1,550/1,170 (GPU/shader/memory). Since the lower shader and memory speeds negate any improvement achieved through a faster GPU clock, we decided to take a step back and stick with the settings achieved without a voltage tweak (720/1,600/1,200 MHz).

Clock Speeds in MHzGPUPercentShaderPercentMemoryPercent
MSI N275GTX Lightning max OC720113.71,600114.01,200105.8
MSI N275GTX Lightning700110.61,404100.01,150101.4
MSI N275GTX Lightning no OC633100.01,404100.01,134100.0

At MSI’s factory overclocked settings, the GPU runs 10.6 percent faster than a reference card. The 1.4 percent increase in memory speed is negligible, though, and the shader frequency isn’t changed at all. Overall, that gives our card a performance boost of 5.5 percent. According to the retail box, MSI’s overclocked NGTX275 Lightning is supposed to perform on par with a GeForce GTX 285. We can’t really refute that claim, since it all depends on the benchmarks, CPU, and graphics driver version MSI used. Based on our own hardware, we still saw a performance gap of one to two percent.

Our maximum overclock made the situation much clearer, with the GeForce GTX 275 effortlessly reaching performance levels similar to those of a reference GeForce GTX 285. If MSI had also pre-overclocked the shader, this would be a really great card. As it is, the NGTX275 Lightning is a card with a very quiet dual-fan cooler, a very potent graphics chip, and a dubious overclocking tool that doesn’t harness the full power of the hardware. If you buy the GTX 275 Lightning, we would actually recommend not installing the Lightning Afterburner tool at all and using the stock (overclocked) settings instead. If you still feel the need to tweak the memory and shader speeds, use eVGA’s Precision utility instead. But beware that you do so at your own risk.

To end on a positive note, we did like that overclocking did not affect the card’s 2D mode, letting the board idle at 300/600/100 MHz.

Graphics Card and Chip ClassFPSPercent
MSI N275GTX Lightning Max OC (GTX 275 1,792MB)1,838.5109.6
GeForce GTX 285 (1,024MB)1,795.0107.0
MSI N275GTX Lightning (GTX 275 1,792MB)1,769.1105.5
MSI N275GTX Lightning No OC (GTX 275 1,792MB)1,694.4101.0
GeForce GTX 275 (896MB)1,677.1100.0

Since MSI equips the GTX 275 Lightning with twice as much memory as a reference card, we also tested the card at Nvidia’s reference speeds (labeled No OC) to see whether there was a performance difference compared to cards with only 896MB of memory. As you can see in our table, the larger memory size offers no benefit over the standard configuration in overall performance. On the other hand, certain games (like Grand Theft Auto IV) can be run at higher detail settings with the larger frame buffer.

With the current generation of drivers, we also encountered some stuttering in Fallout 3, with the scene freezing for a short moment when you turn. Interestingly, this was not a problem with the older GeForce 186 generation, and only seems to plague the combined releases for Windows 7 and Vista.

  • amdgamer666
    Nice article. Ever since the 5770 came out I've been wondering how far someone could push the memory to relieve that bottleneck. Being able to push it to 1430 allows it to be competitive to it's older sibling and makes it enticing (with the 5700 series' extra features of course)
    Reply
  • Onyx2291
    Damn some of these cards run really well for 1920x1200 which I run at. Could pick up a lower one and run just about anything at a decent speed if I overclock well. Good ol charts :)
    Reply
  • skora
    If you're trying to get to the next cards performance by OCing, shouldn't the 5850 be benched also? I know the 5770 isn't going to get there because of the memory bandwidth issue, but you missed the mark. One card is compared to its big brother, but the other two aren't.

    I am glad to see the 5770 produce playable frame rates at 1920x1200. Nice game selection also.
    Reply
  • quantumrand
    I'm really disappointed that they aren't any benchmarks from the 5870 or 5850 series included. Why even bother with tha GTX 295 or 4870x2 and such without the higher 5-series Radeons?

    I mean if I'm considering an ATI card, I'm going to want to compare the 5770 to the 5850 and 5870 just to see if that extra cost may be justified, not to mention the potential of a dual 5770 setup.
    Reply
  • presidenteody
    I don't care what this article says, when the 5870 or 5970 become available i am going to buy a few.
    Reply
  • kartu
    Well, at least in Germany 4870 costs quite a bit less (30-40 Euros) compared to 5770. It would take 2+ years of playing to compensate for it with lower power consumption.
    Reply
  • kartu
    "Power Consumption, Noise, And Temperature" charts are hard to comprehend. Show bars instead of numbers, maybe?
    Reply
  • arkadi
    Well that put things in prospective. I was really happy with 260gtx numbers, and i can push my evga card even higher easy. To bad we didn't see the 5850 here, it looks like the optimal upgrade 4 gamers on the budget like my self. Grade article overall.
    Reply
  • B16CXHatch
    I got lucky with my card. Before, I had a SuperClocked 8800GT from EVGA. I ordered a while back, a new EVGA GeForce GTX 275 (896MB). I figured the extra cash wasn't worth getting an overclocked model particularly when I could do it myself. I get it, I try to register it. The S/N on mine was a duplicate. They sent me an unused S/N to register with. I then check the speeds under one utility and it's showing GTX 275 SuperClocked speeds, not regular speeds. I check 2 more utilities and they all report the same. I had paid for a regular model and received a mislabeled SuperClocked. Flippin sweet.

    Now they also sell an SSC model which is overclocked even more. I used the EVGA precision tool to set those speeds and it gave me like 1 or 2 extra FPS is Crysis and F.E.A.R. 2 already played so well without overclocking. So overclocking on these bad boys doesn't really do much. Oh well.

    One comment though, GTX 275's are HOT! Like, ridiculously hot. I open my window in 40 degree F weather and it'll still get warm in my room playing Team Fortress 2.
    Reply
  • With the 5970 out there seems to be nothing else about graphic cards that interests me anymore :D Its supposed to be the fastest card yet and beats Crysis too!
    Reply