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Overclocking the ATI Radeon HD 4770

Posted on 29th Apr 2009 at 15:40 by Tim Smalley with 12 comments

Tim Smalley
One thing we unfortunately had to cut out of our AMD ATI Radeon HD 4770 review yesterday was overclocking. Understandably, a number of our readers asked why we'd not bothered to overclock the card.

The answer is that we simply ran out of time when we made the decision to double (and triple) check all of our Far Cry 2 performance numbers when the new Radeon came out on top against the cards we'd compared it to. Although the results were theoretically possible - compared to the much-loved Radeon HD 4850, it has a higher pixel fillrate and very similar theoretical shader throughput (it's just four percent lower), we wanted to be not just doubly sure, but triply sure before publishing our conclusions.

Yesterday afternoon, I dragged myself back down into the benchmarking sweatshop that is the bit-tech and Custom PC labs to find out how well our reference card overclocked. It's worth noting that it's not the only Radeon HD 4770 we've got in house - there are a couple of partner cards already and we'll be looking at them in due course - but we've only focused on overclocking the reference card for now.

We first set about overclocking the Radeon HD 4770 using the tools provided to us by AMD - the ATI Overdrive section in Catalyst Control Center. With this, we quickly hit problems... not nasty problems, but good problems - we were limited by the software and hit Catalyst Control Center's maximum clocks of 830MHz core and 850MHz (3,400MHz effective) memory.

The card was showing no temperature or stability issues - everything was very much under control. But we couldn't overclock any further without finding another tool.

We turned to an old friend of ours, RivaTuner, which currently doesn't have official support for the 4770. However, the great thing about the tool is that you can add support by modifying the configuration files. Hilbert from Guru3D was on hand to help us with the hex codes required to get RivaTuner to recognise RV740 - you simply need to add '94B3h' to rivatuner.cfg on the RV770 line under the '[GPU_1002]' section, to make the line read like so:

RV770 = 9440h-9442h,944Ch,94B3h

After doing this, simply restart RivaTuner and it'll allow you to adjust the clocks in the overclocking section. There are some bugs, though - RivaTuner does misreport the ASIC and the core frequency monitoring doesn't work, but I'm sure they'll be fixed in the next RivaTuner release. This is where GPU-Z comes in, because that reports the chip's details and clock speeds correctly.

We could then set about continuing our quest to find the Radeon HD 4770's limit... and we were pleasantly surprised.

Without adjusting the fan speed profiles with the card installed in an Antec Twelve Hundred chassis with no direct airflow to the card, we managed to get the GPU core up to 880MHz and the memory to 985MHz (3,940MHz effective). That's a 17.3 percent core speed increase and a 23 percent improvement in memory bandwidth, which now sits at 63.0GB/sec, which isn't too far off the 4850's 64.0GB/sec.

Overclocking the ATI Radeon HD 4770

In terms of performance - here's what we found...

Crysis

1,280 x 1,024 0xAA 16xAF, DirectX 10, HQ

  • ATI Radeon HD 4770 512MB OC
  • ATI Radeon HD 4850 512MB
  • ATI Radeon HD 4770 512MB
    • 35.0
    • 18.0
    • 33.4
    • 17.0
    • 29.2
    • 15.0
0
5
10
15
20
25
30
35
Frames Per Second
  • Average
  • Minimum

Crysis

1,280 x 1,024 2xAA 16xAF, DirectX 10, HQ

  • ATI Radeon HD 4850 512MB
  • ATI Radeon HD 4770 512MB OC
  • ATI Radeon HD 4770 512MB
    • 28.3
    • 14.0
    • 27.7
    • 14.0
    • 25.8
    • 13.0
0
5
10
15
20
25
30
Frames Per Second
  • Average
  • Minimum

Crysis

1,280 x 1,024 4xAA 16xAF, DirectX 10, HQ

  • ATI Radeon HD 4850 512MB
  • ATI Radeon HD 4770 512MB OC
  • ATI Radeon HD 4770 512MB
    • 25.6
    • 12.0
    • 24.9
    • 12.0
    • 23.2
    • 11.0
0
5
10
15
20
25
Frames Per Second
  • Average
  • Minimum

S.T.A.L.K.E.R.: Clear Sky

1,280 x 1,024 0xAA 16xAF, DX10.1, High Detail

  • ATI Radeon HD 4770 512MB OC
  • ATi Radeon HD 4850 512MB
  • ATI Radeon HD 4770 512MB
    • 35.2
    • 23.0
    • 30.7
    • 22.0
    • 30.3
    • 21.0
0
5
10
15
20
25
30
35
Frames Per Second
  • Average
  • Minimum

S.T.A.L.K.E.R.: Clear Sky

1,680 x 1,050 0xAA 16xAF, DX10.1, High Detail

  • ATI Radeon HD 4770 512MB OC
  • ATi Radeon HD 4850 512MB
  • ATI Radeon HD 4770 512MB
    • 27.8
    • 17.0
    • 25.1
    • 13.0
    • 24.3
    • 13.0
0
5
10
15
20
25
30
Frames Per Second
  • Average
  • Minimum

It's still a little memory bandwidth limited with anti-aliasing enabled, but even then the gap between the Radeon HD 4770 and Radeon HD 4850 has almost completely disappeared. When anti-aliasing is disabled, the overclocked 4770 ends up in another league - not bad for a card that costs £30 less, eh?

And while we're on that topic, we should probably mention that the Radeon HD 4770 is shipping for under £80 already. Prior to the launch, we were quoted an £86.99 retail price by AMD and we managed to find the card for £83 - it's fair to say we were a little hesitant to give a strong buying recommendation on launch day because things chop and change quicker than who's in the manager's chair at Newcastle Football Club.

At this price though, we strongly recommend buying the card over anything else within spitting distance. And that includes the GeForce GTS 250 currently selling for around £97 - it's not far off a 25 percent increase in price and you're definitely not getting 25 percent extra performance in most scenarios!

12 Comments

Discuss in the forums Reply
thehippoz 29th April 2009, 17:45 Quote
wow that's pretty good =] you did alot better than other reviews seen (expreview, vr-zone)
Jojii 29th April 2009, 17:56 Quote
voltage mod time! back to the sweatshop
Tim S 29th April 2009, 18:01 Quote
Quote:
Originally Posted by Jojii
back to the sweatshop
:'(
Combatus 29th April 2009, 23:40 Quote
Sterling work Mr Smalley :-)
Goty 30th April 2009, 04:22 Quote
Looks very nice! (I appreciate the little blurb about the prices, too =P)

I;m with Jojii, though, I would love to see what one of these could do with some slight voltage bumps.
Skiddywinks 30th April 2009, 20:35 Quote
Wow, madness.
storm_temple 30th April 2009, 21:09 Quote
This Card ROCKS!

Ok someone please CrossfireX it
and Overclock + CrossfireX it!@@

Pretty Please:(

another thought SweatShop time
Muahaha
nicae 30th April 2009, 23:46 Quote
NOICE!
Do we have the new 8800GT? The new king of the bang-for-buck?? My happy guess is no! This is only the first card on 40nm, and 8800GT was at US$250. What will ATI give us at US$250?? Let's not forget NVIDIA's next US$250 card either!! :D
perplekks45 1st May 2009, 00:26 Quote
You mean a rebranded 8800GTS based on G80? :p

But yeah, agreed, nice results and impressive overclocking, Tim. ;)
dec 3rd May 2009, 20:05 Quote
maybe a board partner will increase the memory bandwith.....*crossed fingers*
xtreme57 8th June 2009, 06:04 Quote
direct overclocking has a limit ...its one of the best ocier .....raising the voltage will take it to extreme limits ..
http://pcgamersera.com/forum/topic.php?id=16
perplekks45 9th June 2009, 14:52 Quote
Same as today's review of ASUS' 4890, just without warranty. Then again, the cooler isn't up to the task anyways.
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