Does dedicated cache on an NVME drive matter?

[Wallaceman105]

I was looking through partpicker for an NVME to upgrade to, and most seem to just have a "--" in the cache column. 

Only a few seem to have a dedicated amount of cache.

Does cache still matter for NVME? 

[Electronics Wizardy]

What are you using it for?

 

Look at reviews of the drive, there is much more to a drive than the amount of dram in a drive.

[Wallaceman105]

Just my boot drive, some games, nothing flashy. 

Something like this 

https://pcpartpicker.com/product/mNx2FT/hp-ex920-512gb-m2-2280-solid-state-drive-2yy46aaabc

vs this

https://pcpartpicker.com/product/7stQzy/hp-ex900-500mb-m2-2280-solid-state-drive-2yy44aaabc

 

I don't know what the difference is between a drive with or without cache.

Is is just r/w performance, or a longevity thing, or something else?

I know dramless SATA SSDs can take a hit to both when they don't have dram, but I don't know if that translates to NVME drives.

[Electronics Wizardy]

1 minute ago, Wallaceman105 said:

Just my boot drive, some games, nothing flashy. 

Something like this 

https://pcpartpicker.com/product/mNx2FT/hp-ex920-512gb-m2-2280-solid-state-drive-2yy46aaabc

vs this

https://pcpartpicker.com/product/7stQzy/hp-ex900-500mb-m2-2280-solid-state-drive-2yy44aaabc

 

I don't know what the difference is between a drive with or without cache.

Is is just r/w performance, or a longevity thing, or something else?

I know dramless SATA SSDs can take a hit to both when they don't have dram, but I don't know if that translates to NVME drives.

look at reviews for performance.

 

Dramless nvme drives are better than dramless sata drives.

 

Don't worry about endurance it won't matter for desktop uses.

 

 

[Wallaceman105]

1 minute ago, Electronics Wizardy said:

look at reviews for performance.

 

Dramless nvme drives are better than dramless sata drives.

 

Don't worry about endurance it won't matter for desktop uses.

 

 

Thank you for the advice again, but unfortunately, the reviews don't really answer my questions.

I'm not looking for answers about a product so much as about the technology itself, hence bringing my questions here.

And I want to know less for my own usage and more so that I understand.

[Electronics Wizardy]

1 minute ago, Wallaceman105 said:

Thank you for the advice again, but unfortunately, the reviews don't really answer my questions.

I'm not looking for answers about a product so much as about the technology itself, hence bringing my questions here.

And I want to know less for my own usage and more so that I understand.

Its hard to look at the effect of the dram alone, as there are many different implementations, so you can't just look at dram alone. There are many very well preform dramless drives.

 

For a gaming desktop, you don't need a top of the line ssd, and a dramless drive can work well here, but look at the drive, not the technology used.

[Wallaceman105]

1 minute ago, Electronics Wizardy said:

Its hard to look at the effect of the dram alone, as there are many different implementations, so you can't just look at dram alone. There are many very well preform dramless drives.

 

For a gaming desktop, you don't need a top of the line ssd, and a dramless drive can work well here, but look at the drive, not the technology used.

Again, I'm looking specifically to learn about the technology, not for products at this time, but thank you.

[Electronics Wizardy]

Just now, Wallaceman105 said:

Again, I'm looking specifically to learn about the technology, not for products at this time, but thank you.

Have you looked into artices about HMB? It basically lets the ssd store some of the FTL on the systems ram. Helps to increase the performance of a dramless drive a bit.

 

The dramless nvme drives are normally fster than the dramless sata drives, but again, this depends on the exact model

[VeganJoy]

ssds are a complex topic; just on the topic of cahing theres static and dynamic. most drives use dynamic caching but the wd sn550 has a static cache which lets it kick a lot of ass in a lot of ways despite not having dram. asking on an internet forum probably wont get you much into the technical details of this technology, maybe a hardcore storage device blog would help more?

[Wallaceman105]

3 minutes ago, VeganJoy said:

ssds are a complex topic; just on the topic of cahing theres static and dynamic. most drives use dynamic caching but the wd sn550 has a static cache which lets it kick a lot of ass in a lot of ways despite not having dram. asking on an internet forum probably wont get you much into the technical details of this technology, maybe a hardcore storage device blog would help more?

That's kind of what I was looking for, but whenever you type any combination of "cache" with ''nvme" or "ssd", searches just bring up endless pages about how to use NVME as a cache for NAS.

Do you know where I could find something like that?

[Chris Pratt]

33 minutes ago, Wallaceman105 said:

Just my boot drive, some games, nothing flashy. 

Something like this 

https://pcpartpicker.com/product/mNx2FT/hp-ex920-512gb-m2-2280-solid-state-drive-2yy46aaabc

vs this

https://pcpartpicker.com/product/7stQzy/hp-ex900-500mb-m2-2280-solid-state-drive-2yy44aaabc

 

I don't know what the difference is between a drive with or without cache.

Is is just r/w performance, or a longevity thing, or something else?

I know dramless SATA SSDs can take a hit to both when they don't have dram, but I don't know if that translates to NVME drives.

It's all SSDs. NVMe isn't some kind of special type of drive. It's a connection.

[VeganJoy]

try storagereview and servethehome, theyre pretty in depth from what i know but they might not have super technical stuff. probably mostly consumer oriented articles but you never know

[Wallaceman105]

1 minute ago, VeganJoy said:

try storagereview and servethehome, theyre pretty in depth from what i know but they might not have super technical stuff. probably mostly consumer oriented articles but you never know

Thanks, I'll give those a look!

[NewMaxx]

2 hours ago, Wallaceman105 said:

I was looking through partpicker for an NVME to upgrade to, and most seem to just have a "--" in the cache column. 

Only a few seem to have a dedicated amount of cache.

Does cache still matter for NVME? 

Check my signature for a link to more resources then you'll ever want - my Basics guide, buying guides, my subreddit with tons of daily information, package of patents/academic sources, etc.

 

PCPP doesn't always list cache correctly. In any case, DRAM is not as necessary for NVMe drives for a number of reasons. One is that they can use the host memory buffer (HMB) feature, which is using some of your system memory (RAM) for mapping cache. The one exception is the WD SN550 which is a unique creature - you'll have to find my posts on Reddit if you want the full explanation on why it's an exception. Two, NVMe as a protocol is vastly superior to AHCI for solid state devices. Lower latency and more efficient organization means the drives work better so DRAM is less critical. This includes exceptionally fast SLC caching.

 

That's not to say DRAM isn't valuable on them, just that for the casual user it's not a huge deal. On SATA (AHCI) SSDs, however, I feel DRAM is much more important, at least if you intend to use it as your primary drive in any serious system.

[Milanizer]

On 8/15/2020 at 12:54 PM, NewMaxx said:

Check my signature for a link to more resources then you'll ever want - my Basics guide, buying guides, my subreddit with tons of daily information, package of patents/academic sources, etc.

 

PCPP doesn't always list cache correctly. In any case, DRAM is not as necessary for NVMe drives for a number of reasons. One is that they can use the host memory buffer (HMB) feature, which is using some of your system memory (RAM) for mapping cache. The one exception is the WD SN550 which is a unique creature - you'll have to find my posts on Reddit if you want the full explanation on why it's an exception. Two, NVMe as a protocol is vastly superior to AHCI for solid state devices. Lower latency and more efficient organization means the drives work better so DRAM is less critical. This includes exceptionally fast SLC caching.

 

That's not to say DRAM isn't valuable on them, just that for the casual user it's not a huge deal. On SATA (AHCI) SSDs, however, I feel DRAM is much more important, at least if you intend to use it as your primary drive in any serious system.

So if i use a sata SSD for boot drive and other programs, it is still okay right? Like a 250gb 860 evo or MX500.

 

And for gaming, is it better using SN550 or other dramless NVME or is it okay for dramless SSD like teamgroup GX2?

[Mark Kaine]

On 8/15/2020 at 7:54 AM, NewMaxx said:

Check my signature for a link to more resources then you'll ever want - my Basics guide, buying guides, my subreddit with tons of daily information, package of patents/academic sources, etc.

 

PCPP doesn't always list cache correctly. In any case, DRAM is not as necessary for NVMe drives for a number of reasons. One is that they can use the host memory buffer (HMB) feature, which is using some of your system memory (RAM) for mapping cache. The one exception is the WD SN550 which is a unique creature - you'll have to find my posts on Reddit if you want the full explanation on why it's an exception. Two, NVMe as a protocol is vastly superior to AHCI for solid state devices. Lower latency and more efficient organization means the drives work better so DRAM is less critical. This includes exceptionally fast SLC caching.

 

That's not to say DRAM isn't valuable on them, just that for the casual user it's not a huge deal. On SATA (AHCI) SSDs, however, I feel DRAM is much more important, at least if you intend to use it as your primary drive in any serious system.

Eh, some dram less drives can be really slow,  almost at conventional hdd speeds...

 

Then there's also the fact that these kind of drives are usually very cheap and the quality of parts used can vary wildly within each model... That's not to say it can't work for a boot drive but it kind of is a lottery and I generally wouldn't recommend it as there are cheap drives with dram like the MX500 which perform much better and only cost a fraction more. 

 

 

PS: yes I know you're talking about nvme,  but I'm pretty sure the above still applies... The cheapest ones won't be able to keep up with higher priced ones - in general, I suppose!