DDR2 vs DDR3 for phenom II?

[mirage82]

I think I am bringing up an old issue again, but I wonder how this question fits to my situation.

Currently I am using 4GB of DDR2 667MHz, and recently upgraded my CPU to Phenom II 955 on AM2+ mainboard.

While the CPU change boosted the performance of my PC, I started to question the bandwidth of the CPU-memory connection.

Phenom II can be used with up to 1333MHz DDR3 which is the double speed of my current DDR2.

I have seen many benchmarks that DDR3 is not such beneficial on AMD systems, but those articles are before Phenom II and my old 667MHz memory was not even mentioned.

How fast my system could be with DDR3 memory?

Since the memory price is so low these days, would it be worth upgrading my mainboard and memory?

Thanks in advence.

 

[Vette73]

Yes DDR3 would help but not enough to replace the board plus ram to get.

Wait for a AM3+ board that also supports bulldozer then upgrade. That way you get the new chipset, ddr3, and future support for faster CPUs.

If you got a AM3 board now you get ddr3 support but it would gain little else. i.e. not a good return for cost.

 

[VirtualLarry]

You can't just throw DDR3 in your DDR2 mobo. You would have to get a new mobo. I agree, just to change RAM types, that wouldn't be worth it.

 

[jjmIII]

Wait for a AM3+ board that also supports bulldozer then upgrade. That way you get the new chipset, ddr3, and future support for faster CPUs.

....and there is your answer

great advise

 

[fffblackmage]

If you really really want DDR3, you might as well wait for Bulldozer to get the new cpu along with the mobo, rather than waste money on an old platform.

Wooops, someone already mentioned that. Well, either that or just move to SB.

 

[mirage82]

I guess I can wait until 9 series mainboards come out.

Thanks all.

 

[SickBeast]

If I had to guess I would say you would gain ~5% by going with DDR3. The only way it's worth doing right now is if you're going to go with 16gb of ram or something. It's not like AM3 motherboards are expensive. If you can get one for $50 and sell your current board and ram, it would probably work out well for you, OP.

 

[mirage82]

One question remains though, if the benefit of DDR3 is so low on AMD system, would that mean AMD CPU memory controllers cannot utilize the bandwidth of DDR3?

 

[SickBeast]

One question remains though, if the benefit of DDR3 is so low on AMD system, would that mean AMD CPU memory controllers cannot utilize the bandwidth of DDR3?

It's not even an AMD issue. Faster memory tends to only benefit performance by a few percentage points. There are isolated cases where it makes a big difference, but unless you perform those tasks, you're not going to see much of a benefit. Photoshop and video editing are tasks that like lots of fast memory. For whatever reason, games don't benefit much.

 

[veri745]

One question remains though, if the benefit of DDR3 is so low on AMD system, would that mean AMD CPU memory controllers cannot utilize the bandwidth of DDR3?

No, it's just that the extra bandwidth doesn't add that much performance. The latency of DDR3 is not much (if any) better than that of DDR2. Latency is much more important for performance of reads/writes for cache fills.

 

[nenforcer]

The good news is, as you probably are aware, is that DDR3 prices have finally come down to and now typically below those of older DDR2.

That was definitely not the case a few years ago when it was not worthwhile to upgrade older AM2 or even AM2+ boards just to go AM3 DDR3. It was not cost effective but now its the only way to go.

 

[Emulex]

ddr3 is so cheap now it's not funny. 3 sticks of 4gb for $139 (Corsair xms3). or 2 sticks of 4gb SODIMM(laptop) for $69 .

ddr2 isn't really any cheaper. ddr3 will be around for a bit so if you decide to get a i7-2600k you can still rock out with it.

i'd rather rock a core2quad with ddr2 than a amd with ddr3 that's just my opinion.

 

[Anarchist420]

No, it's just that the extra bandwidth doesn't add that much performance. The latency of DDR3 is not much (if any) better than that of DDR2. Latency is much more important for performance of reads/writes for cache fills.

That's true. For AMD CPUs you always want lower latency than more bandwidth. So, actually, the OP would be best off getting high quality DDR2 (800 or 667MHz) and decreasing the clock speed of the ram and the timings to 4-4-4-12-1T.

 

[LiuKangBakinPie]

get a am3 mobo