Confused about modern Samsung 830/840 comparirisins

Cyber Akuma

Cyber Akuma

Gawd
Joined
Jan 3, 2009
Messages
645
When I built my PC in late 2012, the Samsung 840 was just coming to market and the 830 was being replaced everywhere.

At the time, there was debate if the 830 or 840 was better, but most seemed to agree the 830 performed better, and the 840 pro was too expensive.

Looking at SSDs now, I see the 840 EVO, I assumed this meant it was the cheaper/more economical model, but then I saw this comparison chart:
http://ssd.userbenchmark.com/Compare/Samsung-840-Evo-250GB-vs-Samsung-830-256GB/1594vs1387

And it completely and utterly blows the 830 away.

Ok, fair enough, I assumed that since its two years newer it would had to have some improvements by now, even if its the more economical model, but it seems almost ridiculously faster.

Then I compared the 840 evo to the 840 pro:
http://ssd.userbenchmark.com/Compare/Samsung-840-Pro-256GB-vs-Samsung-840-Evo-250GB/1408vs1594

And to my shock.... it's actually worse than the EVO by a little bit.

Ummm... huh? As far as I know, the PRO is still being made too, and costs much more than the EVO. Is this site just completely inaccurate?
 
The 830 was never faster than the 840 Pro. It may have been faster than the 840 non-pro, which was a TLC drive that predated the EVO.

The 840 EVO is a TLC drive while the 840 Pro is a MLC drive. The Pro is unquestionably the better drive. The reason the EVO is faster in some benchmarks is because of "RAPID Mode". This was introduced with and available on the EVO models first, and so many of the benchmarks comparing the EVO vs Pro are done with the EVO using RAPID Mode. Since then, RAPID Mode has become available on Pro models also. If there ever was a time when the EVO had a performance advantage, that time has since come to an end.
 
GotNoRice said:
The 840 EVO is a TLC drive while the 840 Pro is a MLC drive. The Pro is unquestionably the better drive. The reason the EVO is faster in some benchmarks is because of "RAPID Mode". This was introduced with and available on the EVO models first, and so many of the benchmarks comparing the EVO vs Pro are done with the EVO using RAPID Mode. Since then, RAPID Mode has become available on Pro models also. If there ever was a time when the EVO had a performance advantage, that time has since come to an end.
Click to expand...

RAPID mode is a higher-level software driver feature that does heavy caching in your system RAM: http://www.anandtech.com/show/7173/...w-120gb-250gb-500gb-750gb-1tb-models-tested/5 It's usually not enabled in most reviews. If it was, you'd be seeing much higher peak numbers than those reviews/comparisons show.

The EVO models are faster for a few reasons:

1. Faster controller. 400MHz on the 840 Evo, 300MHz on the 840 Pro
2. More cache. Some (maybe all? I forget) 840 Evo drives have more cache than their same-size 840 Pro counterparts
3. The biggest: TurboWrite technology. The 840 Evo drives allocate some of the TLC flash to act like SLC flash to quickly soak up writes faster than even MLC flash. The data is then later re-distributed into the lower-speed TLC flash when convenient. This is why Evo drives come in smaller capacities than the Pro drives (e.g. 500GB vs 512GB). Part of the flash is dedicated to high-speed, emulated SLC mode. And this is why Evo drives are faster.

More slides if you're curious: http://www.pcper.com/news/Storage/New-Samsung-840-EVO-employs-TLC-and-pseudo-SLC-TurboWrite-cache

The Evo is the better drive in every regard except for durability. MLC flash will outlast TLC flash. However, for real-world usage (read: anything but constant high-traffic server workloads) you're just not going to wear out the flash any time in the next few years. And even if you are worried about that, you're probably better off buying the cheaper 840 Evo now and saving the additional money for a faster replacement drive if for some odd reason you wear your 840 Evo out. By the time you write enough data to it to break it, new drives will be much faster and much cheaper.

840 Evo is the way to go unless you're building a server here.
 
I thought the EVO actually had that had a small % of SLC on each TLC NAND. Since Samsung makes NAND they could design their NAND like this.
 
drescherjm said:
I thought the EVO actually had that had a small % of SLC on each TLC NAND. Since Samsung makes NAND they could design their NAND like this.
Click to expand...

Samsung (supposedly) just treats the cells as if they were SLC in that area. Instead of storing three bits across 8 levels of charge in each cell, they just store one bit across two levels of charge in each cell. When you're only dealing with two levels instead of eight levels, you can read and write much faster.
 
AgentQ said:
TurboWrite technology. The 840 Evo drives allocate some of the TLC flash to act like SLC flash to quickly soak up writes faster than even MLC flash. The data is then later re-distributed into the lower-speed TLC flash when convenient. This is why Evo drives come in smaller capacities than the Pro drives (e.g. 500GB vs 512GB). Part of the flash is dedicated to high-speed, emulated SLC mode.
Click to expand...

TurboWrite is necessary to cover up the deficiencies of TLC, which is why it's on the EVO. It's not some bonus that the Pro lacks lol.

AgentQ said:
And this is why Evo drives are faster.
Click to expand...

How so? Performance numbers are pretty one-sided, and NOT in the Evo's favor. http://www.anandtech.com/bench/product/665?vs=965

The Evo has some advantages, such as the faster controller, and neat features, such as Turbowrite, but balanced against the fact that TLC is a LOT slower than MLC, these "advantages" are mostly targeted at simply making up the difference.
 
GotNoRice said:
TurboWrite is necessary to cover up the deficiencies of TLC, which is why it's on the EVO. It's not some bonus that the Pro lacks lol.
Click to expand...

The 840 Pro would also be faster with TurboWrite, would it not? It's a bonus.

GotNoRice said:
How so? Performance numbers are pretty one-sided, and NOT in the Evo's favor. http://www.anandtech.com/bench/product/665?vs=965

The Evo has some advantages, such as the faster controller, and neat features, such as Turbowrite, but balanced against the fact that TLC is a LOT slower than MLC, these "advantages" are mostly targeted at simply making up the difference.
Click to expand...

TLC is definitely slower than MLC, but it's also a lot cheaper. I guess I should have stated "better bang for your buck for the average desktop user" because you can find situations and usage patterns where the 840 Pro performs better.

But look at the Anandtech comparison between the 500GB Evo and the 512GB 840 Pro (which is what I based my buying decision on): http://www.anandtech.com/bench/product/743?vs=964

The 840 Evo has a much higher average data rate in the 'destroyer' benchmark, and is roughly comparable to the 840 Pro in most other measures that actually matter. If you're bench-racing your SSD or have a very specific workload that favors the 840 Pro, then by all means spend the extra dollars on it.

Also, did you read the actual Anandtech review? Take a look at this page and charts, for example: http://www.anandtech.com/show/7173/...w-120gb-250gb-500gb-750gb-1tb-models-tested/7

Also, the conclusion where he mentions that the 840 Evo is his best choice for a consumer SSD.

So yes, if you have a workload in which the 840 Pro beats the 840 Evo, then get the 840 Pro. But for most users, the Evo is a much better use of your money.
 
AgentQ said:
So yes, if you have a workload in which the 840 Pro beats the 840 Evo, then get the 840 Pro. But for most users, the Evo is a much better use of your money.
Click to expand...

I agree with this, the bang for your buck is fantastic on these drives. If you plan on using them for VM storage or host-side caching, you may want to go with the more durable MLC.
 
drescherjm said:
I thought the EVO actually had that had a small % of SLC on each TLC NAND. Since Samsung makes NAND they could design their NAND like this.
Click to expand...

Yes they could, but it would probably be very uneconomical, and cost a lot of R&D to achieve.
 
The 830 is still an awesome drive. I have one in my laptop and in real world use I'd challenge anyone to tell the difference in speed when using the computer with either a 830, 840 EVO, or 840 Pro.
 
Wouldn't EVO perform even better compared to Pro in real world desktop usage? Depending on the benchmark, the drive is saturated with prolonged writes, negating the SLC cachr benefit. That is not how most of us use our drives.

Oh, I don't think most would notice a difference between 90% of SSDs on the market.
 
Meeho said:
Wouldn't EVO perform even better compared to Pro in real world desktop usage? Depending on the benchmark, the drive is saturated with prolonged writes, negating the SLC cachr benefit. That is not how most of us use our drives.
Click to expand...

The way most of us use our drives would be with RAPID mode enabled, which provides write speed advantages far exceeding anything TurboWrite offers.
 
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