I keep an eye out over here from time to time as well. Will get around to answering on the [H] side of the discussion as well shortly. I'm currently in the process of moving a couple of states away, so my rigs and data are packed at the moment.
I only looked at the Metro results so far and there is NO WAY a 780 ti gets that much better performance than the 290x. in fact on techpowerup they got 55 fps for the same MSI 780 ti on the same settings where hardocp is getting 69 fps. I know that is real gameplay compared to the benchmark but it makes no sense for the 780 ti to do 14 fps better than the bench while the 290x is getting only 6 fps more than the bench.
Techpowerup does not explicitly state which level they used for testing, so I do not think that you can make a fair comparison between our data (taken from the Red Square map, from the start up to the end of the shootout) and their data, unless, of course, they did the exact same runthrough. Performance variations within a single game are rather significant, so you can't average a frame rate from one level and then compare it to a frame rate on another level.
I thought the idea was that additional voltage, +50mv, was applied to the OC settings of the 290x in [H] review while no additional voltage was applied when not overclocked. Not sure how that would affect performance numbers of a higher core value but intermittent throttling vs lower core with no throttling, but I think if the bug in the 14.2's was affecting [H] results that what we're seeing from [H] lines up with that bug.
There was a pretty heavy overclock put on the 780ti so we may just be seeing OC 780ti show it's wings, but I think there's more to the performance numbers of the 290x OC in this review which look low independent of the the 780ti.
Look at the performance numbers here for the 290x XFX when oc'd to 1130/5800 vs what identical clocks on the 290x from [H] recent review show.
http://www.hardocp.com/article/2014/02/24/xfx_r9_290x_double_dissipation_overclocking_review/5
XFX 290x (1130/5800)
Metro Last Light -64.6
Far Cry 3 - 48.7
Crysis 3 -52.0
MSI 290x (1130/5400)
Metro Last Light -58.3
Far Cry 3 -44.6
Crysis 3 -42.2
Other games show similar performance drops in the MSI 290x review. Perhaps it's memory anomaly, but the XFX 290x at 1130/5800, decent OC shows a more believable representation of performance of the 290x when OC'd.
There are other factors to consider when comparing numbers from a review that I do compared to one that Brent does. While we do use the same level and similar routine, how I move through that level will not always be the same as how he moves through a level. Also, we do not always record FPS data for the same length of time - for example, his Crysis 3 runthrough is nearly 10 minutes (which I did for quite a while), but more recently I have been curtailing it a bit earlier in the level. If the average frame rate is different on the first half of the map compared to the second, you will see differences in the results between reviews. I would suggest that our average FPS numbers are not great to compare across reviews or reviewers even though they will be great direct comparisons within that particular review (or perhaps to another review done around the same time by the same reviewer). Our observation about best playable settings, in general, will be fairly consistent across our reviews (unless there's an edge case where we make a judgment call).
As for the overclocking side of things, the card did NOT throttle and OC performance at +25mV as well as +40mV was much lousier than it was at +50mV. With regards to the BF4 numbers, I suspect I put a couple numbers in the wrong cell. I was wrestling with that chart for about an hour before I got it right (adding a 4th card to that was NOT fun), so I suspect I put the wrong number in. The OC'ed performance did give a better average FPS and I'll go back through my data and notes once the movers deliver it to my new house (read: might be a bit).
The other thing to keep in mind is that we do our BF4 testing in full 64 player servers, so there is a significant amount of variability depending on the action within the server. Prevalence of explosives, number of deaths and other shenanigans can influence the average FPS number by a significant amount.
It's weird. Because all my R9 290x overclock up tp 1275mhz/1650mhz if I add enough powertune and voltage.
You must have quite a good card. I've tried at least a half dozen 290X's and can't seem to get one to stabilize beyond 1130MHz. I had the MSI one up to about 1180, but it wasn't stable in all of the games I threw at it, so it got knocked down to 1130 before it would no longer crash.
Is it entirely possible they are using different benchmarks of the same game each time they put out a new review?
We don't use benchmarks. We play through a particular level of the game (as specified in the best playable settings chart). As a general rule, we don't change levels between reviews unless there's a good reason. I've explained other sources for variance between [H] reviews above.