HD 2500 and HD 4000

HD4000 is nowhere near a discrete card level... let alone HD2500. You will be playing at the lowest settings, at low resolutions, and games like BF3, non-playable frame rates.

The HD 2500 would be slower than a desktop Radeon HD 5450.

The HD 4000 would be somewhere in between a Radeon HD 5550 and HD 5570; closer to the HD 5550 though. Or a little faster than a Radeon HD 6450.

I don't think that RAM performance is a significant factor in Intel's IGP performance. Unlike AMD, Intel's IGPs are weaker and Intel also has much better memory controllers and cache, greatly minimizing the impact of memory performance. Besides, Intel's IGPs are too weak for modern gaming anyway. Many games can't have playable frame rates even in all minimums, let alone good or even great frame rates.

The 5550 is much more than a little faster than the 6450 and the HD 4000 does not meet nor beat the 5550, ever. It might be around the 6450 DDR3, but not the 5550 DDR3 and especially not the 5550 GDDR5.

believe it or not you you can get playable frame rates with hd4000 in most games as long as you are ok with playing at 720p and low/ medium settings.
most benchmark results prove this

Like I said, many, not all, games can't even get playable frame rates. Sure, some can, but even then, they're still generally poor frame rates with very poor picture quality for a modern desktop/laptop. Having performance at best comparable to a 6450 DDR3 does not help the HD 4000's case when many modern games are simply too much for it (especially many of the popular FPS games).

There's also the act that CPUs such as i3-3xx5 models that have HD 4000 have a much weaker form than the i7s do (the same is true for the other Intel IGPs on various CPUs of different series within each generation), so looking an i7 HD 4000 benchmarks isn't realistic when comparing i3s to similarly priced AMD APUs. When people mention benchmarks of Intel's HD 3000 and HD 4000, they usually refer to i7 benchmarks, so although IDK if those are what you looked at, keep in mind that if they were, they aren't accurate unless you specifically care about i7's IGP gaming performance.

hows the igp performance of the i3-3225 ?
i thought intel hd4000 performance is comparable to radeon 5570 not 6450.
that is because its on par with igp of A8 llano apu which was on par with 5570 itself ?
and sure a 5570 is a good card for gaming at 720p ?

Not true. I play BF3 on my 3570k and I get around 35 fps at 720p everything low. It is playable. I am trying to keep myself from playing it until I get my video card next week. The image quality in MP is a bit too blurry for my liking at low 720p. But it is playable.

The i3-3225's IGP is generally weaker than the 6450 DDR3.

Llano's A8 6550D IGP is only on-par with the 5570 DDR3 if you give the Llano system like dual-channel DDR3-2400 11-11-11-30 or better memory, assuming that you can even get it to run with it.

HD 4000 is not on-par with the 6550 D of the Llano A8s. Not even the i7's HD 4000 which is much faster than an i3's HD 4000 (remember, Intel decided to give very differently performing IGPs the same name, causing great confusion).

That seems like not using Tom's definition of playable. Tom's defines it as frame rates never dropping below 30 and according to their tests, frame rates do drop below 30 even at 720p with everything on minimum/disabled in BF3 MP on even the top versions of HD 4000.

so how will the haswell improve the igp performance ? will it be on par with llano or trinity ?

IDK for sure. There are rumors of Haswell having a huge improvement in IGP performance, but beyond performance, Intel's drivers also suck. Unless they are also improved greatly, it might not matter if Intel met or beat AMD in GPU performance because AMD now has their drivers mostly great and would be able to win overall anyway.

Besides, once Intel catches up, AMD will simply take a leap over them. AMD's next APU series is supposed to have a Radeon 7750's worth of performance and would probably beat the crap out of Haswell so long as AMD can keep it being fed with the memory, something that should be fairly easy if they make some improvements in their memory controllers and cache.

Unknown. Current speculation is anywhere between 30% - 50% increase in performance over Intel HD 4000. However, games tends to also push the performance envelope so the net gain performance for Haswell's IGP for next year's highly anticipated games could relatively small. Of course, for games that have been released this year or prior years that increase in performance would pretty decent.

For the hell of it, I decided to play Mass Effect 3 from start to finish on my laptop using the HD 3000 instead of the nVidia 550m. There is a definite performance difference between the two, but I found the HD 3000 to be capable enough for me to play ME3 on Insanity at 1366x768 resolution. The Intel HD 4000 would have boosted gaming performance and Haswell's IGP would further increase performance as well.

The Intel HD 4000 has a 35% performance increase over the HD 3000. If Haswell's IGP can get a 35% increase in performance over the HD 4000, that would mean the Haswell's IGP performance could be 82% greater than the Intel HD 3000. However, it would still be considered to have entry level performance.

If Intel could somehow increase performance over the HD 4000 by 300%, then that would be considered a lightweight mainstream graphics card performance. It will happen, but it probably won't be until around 2017 or 2018. By that time Intel's IGP will still be considered entry level.

atleast hd 3000 and 4000 are more capable than a 5450.
its interesting to think due to lack of funds i had to play games like ME2, GTA4, RE5, MW3, crysis 2, MP3 etc on a 5450.
and i made them all playable on 720p except gta 4 which is crap port anyway.
now my 7750 owns every game out there except for gta 4 and SR3 which is laggy dunno why

HD 3000 isn't really any better than Radeon 5450. The i3's version of HD 3000 is weaker than a 5450.

and how is the intel hd graphics of pentium sandy bridge of my G630 cpu ?

I don't know exactly where it sits, but it's definitely not even a third of a Radeon 5450 in performance.