New cost-effective DDR5 memory 'HUDIMMs' show around 50% reduction in throughput with single subchannel — Two HUDIMMs are as fast as a single stick of regular DDR5 RAM
Posted by sr_local@reddit | hardware | View on Reddit | 120 comments
dogancanAtRigyd@reddit
So we're solving the DDR5 pricing problem by making RAM that's half as fast. truly the "we have DDR5 at home" of memory solutions. for general desktop use sure whatever, but anyone doing ML inference or training where memory bandwidth is already the bottleneck is going to feel this immediately. might as well tape two calculators together and call it a workstation
spicesucker@reddit
The irony of taking DDR5 memory where one of main innovations over DDR4 was dual subchannels and going back to a single subchannel is hilarious.
I know there’s more to DDR5 than just subchannels, but surely this must be worse than DDR4.
JJJBLKRose@reddit
I think you're making the wrong comparison. It's not this DDR5 vs DDR4 since they're not making much DDR4. It's this DDR5 vs not being able to afford any memory, which in that case becomes more useful.
little_lamplight3r@reddit
Reading your comment one might think ddr4 disappeared and cannot be bought anymore
S_A_N_D_@reddit
It is scarce, and most modern components are going to be centered around motherboards and chipsets designed for ddr5.
little_lamplight3r@reddit
Maybe it's just my region but shops are full of new unopened ddr4 here in Europe, major retailers and smaller businesses alike. The used market is even better, although I know it's not for everyone
GabrielP2r@reddit
How is the pricing for you? Thinking about building a PC and ddr4 is the only logical choice when it comes to price perfomance
little_lamplight3r@reddit
Pretty terrible. A 6000/32 set of DDR5 (2x16 GB) goes for 400€. That's the same as a Ryzen 9700X and a suitable motherboard combined. A similar set of DDR4 (3200 MHz) is "only" 220€.
GabrielP2r@reddit
Shit still wayyyyy to much, fuck this
Strazdas1@reddit
Local retailer here has plenty of DDR5, DDR4 and even has some DDR3 kits.
little_lamplight3r@reddit
Same here.
Strazdas1@reddit
Its not scarce. Both DDR4 and DDR5 are easily available, just at a high price.
cakemates@reddit
look at it this way, with this people get access to ddr5 cpus which are significantly better than ddr4 ones.
Concillian@reddit
The "good stuff" for desktop is all gone (except through the used market.) What can be bought now is a shadow of what DDR4 was when people were buying it and when all the DDR5 vs DDR4 comparisons were made. If you look at thos comparisons it looks like DDR5 is a measurable advantage, but DDR4 isn't too far behind... The problem is that you can't get DDR4 like that anymore. All the stuff you can get now is way less performant, so it probably performs close to this garbage DDR5 in the article.
There is no good solution.
FCCRFP@reddit
It is extremely scarce in DC amounts and quality.
Exist50@reddit
No one's using this for DC.
corruptboomerang@reddit
It's not about making it better or worse then DDR4 for many applications DDR3 would be fine, if you had sufficient quantity of RAM. This makes crappy DDR5 that trades quantity for quality, and as with many things, quantity has a quality all of its own.
Wonderful-Lack3846@reddit
The funniest thing about this will be that they will be like ~80%-90% of normal DDR5 ram pricing
AtLeastItsNotCancer@reddit
Price/GB should be similar, it's just that this allows them to make lower capacity sticks.
IIRC the current DDR5 chips that go into typical PC memory come in 8/16/24Gbit capacities, and you need 8 of them to make a full 64-bit wide module. If you only use 4, that allows you to make 4/8/12GB sticks, presumably to be used in low-end OEM machines that will only come with a single stick installed. So basically equivalent in bandwidth to single-channel DDR4. Such progress!
Dr_Cunning_Linguist@reddit
Oh..Brave New World!
Die4Ever@reddit
I guess we could see computers with a single 12GB stick, it's enough RAM that the computer should feel fast enough for casual users
reddit_equals_censor@reddit
this is WRONG. having HALF the memory bandwidth and other downgrades from this leads to a BIG performance reduction in gaming. some games more than others:
https://www.youtube.com/watch?v=_nMu1KFkOC4
hardware unboxed tested single channel ddr5 vs dual channel ddr5 both non scam versions of ddr5, which should be very close to this hudimm scam IF you were to use 2 modules.
on average 1% lows get reduced by 16%, but in some games it is a LOT more.
horizon zero dawn remastered shows a 33% reduction in 1% lows with just one stick of non scam ddr5 vs 2.
marvel rivals 1% lows drop by 34% and average fps by 34% as well.
in actual numbers marvel rivals drops from 195 fps 1% lows 145, so an ok performance for a competitive game to 129 fps and 1% lows 95%, which is a shit experience in any competitive multiplayer game.
so this hudimm scam MASSIVELY effects people's desktop experience. MASSIVELY.
a 34% reduction in a game you might play is night and day difference.
hudimm is a criminal scam by this shit industry.
hardware2win@reddit
Exist50@reddit
I don't see how budget gamers would benefit.
Y0tsuya@reddit
Nothing with this LLM datacenter buildout is worthwhile for us.
disposableh2@reddit
It's not great, but not horrible either. It's not aimed at enthusiasts or power users, it's aimed at people who need a new system and need cheaper ram.
For the same ram chips that would create 1x 16gb stick, they can create 2x 8gb sticks instead(selling them as individual sticks) and at least allow people with basic computing needs to get a cheaper system with modern hardware (since modern hardware would need ddr5).
If you wanted a new system with basic requirements (like say a home Nas) you would either buy an older system with ddr4, or buy a new system where the ram costs half the entire build. This aims to help reduce that cost, where you don't need blazing fast or high capacity ram.
It's not an ideal solution, but it's something to help fulfill the lower end, basic computing needs.
Exist50@reddit
1x16GB normal DIMM would be cheaper than 2x8GB HUDIMM. This only makes sense if you're just shipping with 1x HUDIMM.
crab_quiche@reddit
Assuming 16Gb chips you can just configure them in x16 and get 8GB DIMMs that will perform as twice as well as these, this only makes sense for making 4GB DIMMs using two x16 chips for ultra budget systems.
F9-0021@reddit
It'll be awful for any kind of workload more demanding than just turning the system on and opening a browser. But that's probably the point. Get the peasants on cheap internet terminals while the people who actually need or want local performance will be scalped for it.
kaszak696@reddit
Before that, shitty OEM PCs and laptops had a single lonely stick of single channel RAM. Now, with this groundbreaking innovation, they'll have a a single lonely stick of half-channel RAM.
YairJ@reddit
I don't really understand the costs of manufacturing these, but wouldn't two DIMMs cost more than a single one with the same chips? Even without considering the complexity from just having more products.
shawnkfox@reddit
I'd want to see how thus actually affects gaming performance. My bet would be you'd barely notice a difference in most cases. The most important factor is latency not total bandwidth, and there is no difference in latency.
That said, how much of a price difference will it make? I guarantee you it won't be 50% cheaper. Maybe 20% at most.
ariolander@reddit
Seems like something an OEM would put in a rebuilt, not tell the consumer about, advertize only the capacity of the RAM, and still charge full price for. So many people are going to get scammed by these.
nuked24@reddit
I'm gonna see so many of these in Dells and HPs in 10 years, every office PC is going to use them
red286@reddit
"Hey guys, we figured out how to turn DDR5 into DDR4!"
Strazdas1@reddit
We figured out how to sell DDR4 at DDR5 prices!
iBoMbY@reddit
And here I thought it was the memory chip shortage that was making memory expensive? How do these single channel chips save 50% of the silicon, to make them more affordable?
phire@reddit
Because memory chips come in a minimum size, and the price per byte isn't linear.
The smallest DDR5 chips are 16gbit (2GB each). So if someone wants to sell 8GB DIMMs, they need to only use four memory chips.
This is possible, they sell x16 chips for this reason (where each chip provides 16-bits of the 64-bit bus) . But the x16 chips are more expensive than the common x8 chips.
This hew HUDIMM "hack" "solves" the problem by using only four x8 chips, and only populating only half of the 64-bit bus.
Also allows them to use four 32gbit chips on 16GB HUDIMM modules, which is often cheaper than eight 16bit chips.
Strazdas1@reddit
Well, they shouldnt be selling 8 GB DIMMS then.
Low_Chemical4746@reddit
As far as I can see, the article does not claim it's 50% cheaper, just 50% the speed. It's just an ambiguous "reduced cost"
Verite_Rendition@reddit
Half a DIMM? Wouldn't that just make this a DDR5 SIMM?
teen-a-rama@reddit
This is what you’d be served, plebs
Noreng@reddit
Might as well go to 4 HUDIMMs then. That way you'll get full bandwidth
Antagonin@reddit
You won't though. Each pair of sticks will be sitting on the same subchannel.
Noreng@reddit
No? Each stick will connect to a 32-bit subchannel
crab_quiche@reddit
You would have to have two different SKUs of these to make that work.
AtLeastItsNotCancer@reddit
LMAO imagine buying a 4 module kit of these, and then having to pay attention to which exact stick goes into which slot so that you don't accidentally cut your bandwidth in half.
phire@reddit
And then the two sticks would get the exact same performance (yet cost more to manufacture) than a single DDR5 DIMM.
The concept only makes sense if you plan to ship computers with only one HUDIMM installed.
Buris@reddit
You need a processor that’s capable of quad channel memory though, so nothing that’s currently on the market (until you get to Threadripper, Xeon, or Epyc)
Noreng@reddit
No? Each stick will connect to a 32-bit subchannel
Buris@reddit
If you designed it that way, that might work. But the processors and the boards aren't designed that way. It has to report to the motherboard that it has a 64-bit channel.
Noreng@reddit
The current prototypes are running on Intel CPUs with UDIMMs, by disabling a subchannel.
Exist50@reddit
So running at 2x32b instead of 2x64b.
Ar_phis@reddit
All comes down to price.
Many applications don't (fully) utilize the bandwidth benefit of dual-channel memory.
GN did a test a decade ago where games generally didn't benefit, while some workloads showed a noticable increase with dual-channel.
It ranges somewhere between 0% to 30%.
Open world games will probably be worse than anything that loads the entire textures, etc. into the RAM upon start.
Exist50@reddit
If you don't need dual channel, you'd be better off getting a single stick rather than 2x half channel sticks.
ThisCommentIsGold@reddit
MISSING AN IMPORTANT BIT OF CONTEXT
PossibilityUsual6262@reddit
Why did they even bother?
Exist50@reddit
What do you mean? That's replicating basically the same thing these DIMMs ship with. Seems like a valid way to test.
Tokena@reddit
4 thy clicks.
PossibilityUsual6262@reddit
I don't like it, make them aware that i dont like it.
Exist50@reddit
So what's the problem? They simulated the config these HUDIMMs come with, and tested it. And it performs exactly as you'd expect it would.
Cheeze_It@reddit
Did they benchmark it?
Born2Rune@reddit
Don't want sub-par hardware? then stream and like it, peasants.
guigr@reddit
Yes. This absolute massive performance is not enough to do anything on a PC obviously
Hipcatjack@reddit
“own nothing: and be happy” 🙄🤬
Born2Rune@reddit
Yep. We will be paying subscription fees for our phones and them having to return them when the new ones come out.
Slava_Tr@reddit
This is excellent memory for Zen 5 with a single CCD, which has an internal bandwidth of 60 GB/s. So Zen 5 is more sensitive to latency than to bandwidth. And with this memory, since those characteristics are similar, there shouldn’t be any issues. It seems like this is memory designed specifically for the most popular single-CCD Zen 5 PCs today. It could be a lifeline for gaming PCs during this memory shortage
This memory will be fully sufficient for the 9800X3D. AMD itself recently promoted that the difference between high-end DDR5 and cheaper kits is only about 1%
Itwasallyell0w@reddit
1% in cherry picked benchmarks. In competitive games slow vs fast ddr5 can boost 1% lows up to 50% even on 3d cache CPUs. Most benchmarks are done on single player games with no main thread bottleneck.
Slava_Tr@reddit
https://youtu.be/_nMu1KFkOC4?t=483
The 9700X with a single DDR5 6000MT/s stick has excellent 1% lows in CS2. And that single stick will have slightly lower bandwidth(48 GB/s vs 60GB/s) than those two HUDIMMs
Itwasallyell0w@reddit
cs doesn't care about ram speed much tbh
Slava_Tr@reddit
Can you give me links to any competitive games that would benefit from this on Zen5 with single CCD? Because I don't know of any. I'd like to see that 50% you mentioned
Speed converts to memory bandwidth, which is vital for integrated graphics performance. For example, single-channel regular DDR5 at 5600 MT/s provides 44.8 GB/s, while 6600 MT/s delivers 52,8 GB/s. Dual-channel is exactly double that
Itwasallyell0w@reddit
https://youtu.be/Fy8H0iSptGo?is=frlRP_n8mcOQPjg0
GPU utilization up to 20% more with tuned ram on x3d CPU.
Now the instances where ram speed matters the most are very hard to benchmark.
The best way to tell is when you play competitive games and your games and observe the low frames in intensive fights.
Slava_Tr@reddit
Just better timings
Itwasallyell0w@reddit
better timings results in better speed? I think you are confusing frecuency with speed...
Slava_Tr@reddit
Frequency and speed are directly dependent on each other. Open Wikipedia about RAM timings. In short, it is the latency mentioned in the first message. Speed and latency can be different
Itwasallyell0w@reddit
speed is the sum of it all, lower latency results in faster memory.
I wasn't talking about frecuency speed I was talking about ram speed which includes latency and frecuency both. Anyway the point stand.
Faster ram is better than slower ram and very noticeable so even on x3d CPUs.
Slava_Tr@reddit
That's not true
DDR3 has a typical latency of 13ns, while the much faster DDR5 has 60–80ns out of the box
Itwasallyell0w@reddit
yeah because it has lower latency at higher frequency.
You are a master a cherry picking without context when you are proved wrong😂😂😂
Slava_Tr@reddit
Where am I wrong here? My initial take is that this HUDIMM memory will be great for a single-CCD Zen5. It’ll have similar timings to DDR5, just with lower bandwidth. You’ll be able to find HUDIMM with decent timings or tune them anyway, so that’s not the issue. My point is that this memory will be optimal for Zen5 and cheap because it’s not suitable for AI due to its low bandwidth
There was no context needed for the Ryzen ad because it was just an example. I thought you were using it to dispute the main point, rather than just some illustrative part of it. Which has its other nuances, that’s a whole different story
Itwasallyell0w@reddit
https://youtu.be/G4515gWIL6g?is=MGki1W9z1IiT8LNH
consistent 20% better 1% lows the 50% its only felt in very intensive scenes which is hard to benchmarks.
In Apex legends you can drop under 100 fps in last circle with 10+ teams left that's when the main thread gets hard bottlenecked, tested myself and get up to 50% more frames in this scenario with xmp on off.
Slava_Tr@reddit
This is exactly what I was writing about. Here, memory with better timings is superior to memory with higher bandwidth but worse timings. And why 4800 MT/s has significantly worse timings, yet the difference is 20%
Also, where competitive games with this the 50%? Why is it hard to benchmark if it would be immediately visible in the numbers? In other cases, it can be recorded
And when we compare single-channel 6000 MT/s with good timings to dual-channel, the difference is no longer substantial
Itwasallyell0w@reddit
it is hard to benchmark because it is not a preset benchmark and every game is different in different places etc. And when it happens the frames are all over the places, jumping for 300 to as lows as 100. So yeah it is really more of a feel thing that can be validated by looking at the frametimegraph.
The point is that speed ram speed matters even on x3d CPUs, be it by frecuency or latency.
a 7800x3d with tuned ram will perform on par or better than a 9800x3d with slow ram.
Slava_Tr@reddit
It is because of the lower memory latency in tuned RAM, rather than higher memory bandwidth. In fact, on the 7800X3D, bandwidth is lower at 53 GB/s vs 60GB/s for a single CCD. This again proves what I wrote from the very beginning
Itwasallyell0w@reddit
No, you said that the difference between low kits and high ends kits is only about 1% which is totally untrue and misleading.
Slava_Tr@reddit
So you’ve just confirmed that it’s true for 1% lows, and the only real difference is in the 0.1%. This refers to the example of being memory bandwidth bound
As I mentioned before
They’re releasing different HUDIMM modules with various timings. The fact that they’ll have half the bandwidth is actually a great fit for Zen 5 on a single CCD. A HUDIMM kit with good timings will outperform faster DDR5 with bad timings
Itwasallyell0w@reddit
Unless it reaches 6000 MHz with lower than 36 cl it won't outperform shit.
Itwasallyell0w@reddit
https://ibb.co/WNddS2WJ
0.1% lows would be a good measure for when the CPU stutters which shows that faster ram is better when it is needed.
Slava_Tr@reddit
Can you give a link to the 50% gain? I’m genuinely interested. It could be a specific case
imaginary_num6er@reddit
Once again, Intel is screwed by relying on higher memory speeds
inverseinternet@reddit
Nah, you completely misunderstand the point in this case.
Constellation16@reddit
Please someone explain to me why these even exist? Existing x16 8GiB DIMMs also only have 4* chips, but you keep the full bandwidth..
digital_n01se_@reddit
paying more than DDR4 to get less bandwidth than DDR4?
floorshitter69@reddit
2x 8gb half sticks in dual channel runs the same as a single 16gb in single channel.
It kind of doesn't make any sense. Basically it is a way for a temu vendor to sell a counterfeit pc with a half stick that functionally works.
And consumer pc hardware doesn't run higher than dual channel.
venom21685@reddit
Yeah the only situation where this makes any improvement is when comparing 2 mixed sticks with 1 traditional stick.
For example, a 16GB UDIMM and 8GB HUDIMM will have more combined bandwidth than a single 24GB UDIMM. (1.5 channel vs 1 channel)
explosiv_skull@reddit
They found a way to shrinkflate the RAM.
TheOtherWhiteMeat@reddit
Pretty ridiculous. Unless it's literally half the price, it's still worse performance per dollar.
ClerkProfessional803@reddit
I read this and immediately thought of subsidized ram for some reason. We've really entered the poor people ram era. And of course it's Asus.
corgiperson@reddit
And they’re not going to sell at half the price though. So unless you’re super strapped for cash and need to make a cut anywhere possible, this is just terrible value.
-CynicalPole-@reddit
dude, even at half the price you buy garbage with zero resell value and crippling the fuck out in most gaming performance on most CPUs. I bet even X3D parts with choke on such slow memory.
DynamicStatic@reddit
Sure, but remember that a lot of people aren't really gaming. This is not a gaming sub.
corgiperson@reddit
Yeah. That’s a good point too. Nobody going to buy these things off you once normal RAM is available again.
nithrean@reddit
those who are doing it are not trying to give consumers "value"
darkpigvirus@reddit
I have no choice my friends, I will take it 😆
Tired8281@reddit
I have often wondered why we can't build Double DIMMs, with two channels of memory on the same physical stick.
Wait_for_BM@reddit
Almost always, it is a matter of cost and physical feasibility.
The DIMM have to have the extra pins allocated for data bus for the 2nd channel. For signal integrity, extra signals always require additional ground/power pins to work reliable at high speed. i.e. physical size has to be wider or go to higher density connectors (cost).
Now you also need more or more complex memory controller to support the extra channels.
DDR5 has a narrower bus but faster, so that's how they managed to do 2 channels.
crab_quiche@reddit
That’s what normal DDR5 is
ImSpartacus811@reddit
That's what the new CAMM2 standard does. As a result of getting dual channel in a single CAMM2 module, compatible motherboard only come with a single CAMM2 "slot".
OttawaDog@reddit
IMO, this will mostly end up in prebuilts sold to people that don't know anything about PC specs.
Journeyj012@reddit
so they've remade ddr4?
Thesadisticinventor@reddit
They basically split a single channel of ddr5 across 2 dimms. Half a channel each.
Key-Invite5027@reddit
Because Hynix, Samsung, and Micron can freely manipulate memory prices, products like these were created.
Since insufficient capacity is the primary reason for poor performance, this is unavoidable.
saucerman@reddit
Wait, shouldnt it be one HUDIMM is as fast as two sticks of regular DDR5 ? Are we going backwards
Igor369@reddit
So it is like... DDR4 for DDR5 slots... amazing... wow...
ash_ninetyone@reddit
I mean. I get this might be attractive at anyone who just needs cheap RAM to shove in a machine that doesn't need faster sticks.
But this kinda feels like dealing with a cut by amputating a leg.
RAM was one of the most affordable bits of hardware out there until data centres practically bought the entire supply chain.
crab_quiche@reddit
This only makes sense for ultra budget systems that only need two DDR5 chips in x16 config, for anything else it would just be better and/or cheaper to run a normal config.
timerski@reddit
Yay, we're getting cheaper, crippled components!
GalvenMin@reddit
Bold of you to assume they'll end up cheaper!
Dazzling_Jinn@reddit
Dumb idea. Will not be popular
Logical-Database4510@reddit
Vcache go brrr
If these things get popular AMD is going to print money with a 9600x3d
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