System upgrade - DDR4 vs DDR5

[brucewtb 250]

I put my current system together about the same time as Ray back in 2018 with similar parts and it is also time for an upgrade.  However, I need to save on costs so am hoping to keep as much as much of my current system as possible and only replace the Motherboard, CPU and (probably) the GPU.  This means keeping my DDR4 ram and installing a DDR4 compatible motherboard - probably the ASUS ROG Strix Z790-A which is a bit of a downgrade for me as in the past I have always gone for high end boards (my current board is an ASUS ROG Maximus XI Extreme XI) but current high end boards don't support DDR4 and are quite expensive. So are there any any significant drawbacks in sticking with DDR4 and as a consequence a mid end MB?  I note that the upcoming Intel Gen 14 CPUs will support DDR4 ram. Any thoughts appreciated.

Bruce

 

[Dave_YVR 997]

 I upgraded my CPU and mobo earlier this year and went through the same decision process. I elected to stay with my DDR4 as I still don't think there are big enough gains to be had to make the jump to DDR5 without well more than doubling the cost of the ram and motherboard and even then you would see the difference only in certain benchmarks. 

[Flyfox 128]

2 hours ago, Dave_YVR said:

 I upgraded my CPU and mobo earlier this year and went through the same decision process. I elected to stay with my DDR4 as I still don't think there are big enough gains to be had to make the jump to DDR5 without well more than doubling the cost of the ram and motherboard and even then you would see the difference only in certain benchmarks. 

I have exactly the same experience and I am still very happy with the performance of my DDR4 based system (i5 13600K and RTX3090), which I exclusively run in VR mode.

[tfm 192]

Everything I read about this says the same thing!

I don’t spend time fiddling around with these things any more, but I remember back in the day obsessively hunting out the fastest RAM with the tightest timings I could find, and measuring the effect on FPS in FS9/FSX. It did make a worthwhile difference (especially, as I recall, getting from command rate T2 to T1). 

Just out of curiosity, if I turn off the XMPii settings on my current DDR5 RAM so that it runs at base settings, I do get reduced performance which impacts the frame rate .

…. one possible inference being that RAM speed / latency hasn’t disappeared completely as a potential bottleneck, even if it’s more likely to be overlooked these days 🙂

Edited October 4, 2023 by tfm

[Biggles2010 343]

8 hours ago, brucewtb said:

So are there any any significant drawbacks in sticking with DDR4 and as a consequence a mid end MB?  I note that the upcoming Intel Gen 14 CPUs will support DDR4 ram. Any thoughts appreciated.

Some of the more carefully controlled tests have shown a small improvement in fps in various games with fast DDR5 compared with fast DDR4, with the emphasis on small. Typically about 2 - 3 fps, some games about 5 fps.

People tend to become obsessed with memory speed, but ignore latency, which is much better with DDR4.  I would suggest if you have good DDR4 such as 3600 C16 or better, then the gain from the most typical DDR5 at 6000 C36 would be small, and more expensive. However, the costs of some DDR5 are getting more reasonable and both speeds and latency are improving.  But those speed improvements still command a premium price. And motherboards for DDR5 are still notably more expensive.

If your choice of CPU and GPU are going to be the very best available, then very fast DDR5 would make sense, but at a high cost.  However, if cost effective performance is the priority, this usually means one step down from the best available components, with a notable cost reduction and only a small performance penalty.  If your existing DDR4 is reasonably fast, then it would be a sensible choice to continue using it and also save on the motherboard. The difference when in use will be very small.

 

Edited October 4, 2023 by Biggles2010

[brucewtb 250]

16 hours ago, Biggles2010 said:

 .....if you have good DDR4 such as 3600 C16 or better....

That is the RAM I currently have.  My dilemma is whether to change the GPU from a 3080ti (which I have only had for 2 years) to a 4090. If I do then I will just have to find savings somewhere else. I run my current system at 4K and the problem with the 3080ti is that VRAM at major airports (less concerned about FG) I can be right up against the 12gb limit and I get a spike in system RAM use to 24gb or more.  Thanks guys for your observations.

Bruce

[tfm 192]

Why is high VRAM use a bad thing? Surely it’s exactly what you want to see as it shows the system is using all available resources!

I went from a 3080ti to a 4090 but my reason was to enable frame generation in DX12. This (literally) doubles the frame rate as experienced in the sim, by interpolating an algorithm-derived frame between rendered frames based on what it thinks the next rendered frame will look like - and is a game-changer. 

Edited October 5, 2023 by tfm

[Biggles2010 343]

8 hours ago, brucewtb said:

My dilemma is whether to change the GPU from a 3080ti (which I have only had for 2 years) to a 4090.

I've been going through the same kind of mental gymnastics as you. I have a 3080 12 Gb, but there is little doubt the best card around at the moment is the 4090. It's a massive step up from either of our cards, not just in vram, but in sheer processing power, as well as the benefit of frame generation from 4000 series cards as tfm mentioned. While the 4090 is still very expensive, it can make sense in terms of performance per pound or dollar spent compared with lesser cards which cost less but are still quite a big outlay for a more limited performance. The 4090 can mean other additional costs though, like a new power supply, depending on what you have already.  Sorry this is only providing thoughts rather than answers, but for most of us it's a balancing act where you can get the performance required, but it's usually going to be expensive.

[Ray Proudfoot 9,039]

23 hours ago, brucewtb said:

My dilemma is whether to change the GPU from a 3080ti (which I have only had for 2 years) to a 4090. If I do then I will just have to find savings somewhere else.

Bruce, other things you need to consider are card size and a beefy power supply. Will your case accommodate a 4090? I had 3mm spare in mine! The 4090 needs a minimum of 850W. Is your current PSU enough?

Hard to say if DDR5 will be a noticeable improvement over DDR4. The 4090 will be better but not by a huge amount over your 3080Ti. I came from a 1080Ti so that together with a much faster CPU, RAM, SSD all contributed to a much faster system.

A system is only as fast as its slowest component. I wouldn’t go for a 4090 until you have a faster CPU which you don’t mention.

[tfm 192]

20 hours ago, Ray Proudfoot said:

The 4090 will be better but not by a huge amount over your 3080Ti

That wasn’t my experience going from a 3080Ti to a 4090: frame generation doubled the frame rate in DX12. 

[Ray Proudfoot 9,039]

4 hours ago, tfm said:

That wasn’t my experience going from a 3080Ti to a 4090: frame generation doubled the frame rate in DX12. 

You’re describing something that only applies to MSFS. Bruce hasn’t mentioned what sim he uses but if it is that sim then I agree the 4090 would surpass his 3080Ti.

[tfm 192]

4 hours ago, Ray Proudfoot said:

You’re describing something that only applies to MSFS. Bruce hasn’t mentioned what sim he uses but if it is that sim then I agree the 4090 would surpass his 3080Ti.

Yes that’s true! I forgot about p3d - haven’t used it for ages. 

[AnkH 2,282]

Had the same question and finally went for an i5-13600K on a Z690 Gigabyte Gaming X DDR4 MoBo to be able to re-use my 3200 CL14 DDR4 RAM (2x16GB Sticks). Along came a 4080 because I was not ready to pay the upgrade price for the 4090 and as I am "only" on 1440p, I thought that the 16GB VRAM will be enough. 

So far, utterly happy with the "new" rig, it was a huge boost over my former 8700K plus 1080Ti build in MSFS. Notably of course also due to frame generation. 

In Benchmarks such as 3DMark, I loose about 5-10% compared to 13600K builds using DDR5 in CPU heavy scenarios, in GPU heavy scenarios, the loss is within margins (of course) and thanks to frame generation, I could not care less about those 5-10% in CPU heavy MSFS scenarios 😉 

[brucewtb 250]

Just to clarify I mainly use MSFS2020, have a very large case and a Corsair 1000W power supply and plan to keep my H115i AIO cooler (Corsair sell an adapter kit to enable this)  - my last build was over speced  for the time.  My H115i cooler easily copes with the demands of my current system so I hope there will be enough headroom for an upgrade. I would like to spread the cost of this thing over two tax refunds ie what I got back in July this year and what I will get in July next year.  So I may get a 4090 now and the CPU/MB next July or the other way round.  If I just add a 4090 to my current 9900KF build I will be massively main thread limited and expect to get zero FPS inc (apart from what FG will deliver) but will gain a lot more VRAM.  If I do things the other way round it is less certain how things would pan out in the short term depending on what numbers increase intel Gen 14  CPUs deliver (although the word around the traps is "not very much") but there would be some FPS inc maybe 10-15%. One complicating factor for keeping DDR4 RAM is that the new boards natively supporting intel Gen 14 CPUs appear to be only DDR5 compatible (a bios upgrade will be needed for current models).  Once this is all put together there should be a substantial increase in performance over my current system - although what I actually see will be limited by my 60Hz 55 inch Sony 4K  TV which is the reason I am less fussed by FG in the longer term.  One advantage of getting the GPU first would be that I could see how my current case/cooler handled the additional load which could influence my ultimate choice of CPU.

Bruce

[Bob Scott 7,746]

On 10/9/2023 at 9:28 PM, brucewtb said:

Just to clarify I mainly use MSFS2020, have a very large case

Make sure you measure it anyway.  I have been using large, full-size Coolermaster HAF932 and HAF-X cases for years, and was very unpleasantly surprised to find the ASUS 4090 GPU I got during the height of the shortages was *far* too long to fit into those big cases due to the placement of the non-removeable hard drive cages.  Most of the 4000-series cards are truly ginormous.  I was able to fit an nVidia 4090 FE GPU into the HAF cases, which I did for my MSFS/XPlane machine, but I had to very reluctantly go to a different case for my 13900K/4090 P3D build.