Disk

Anything related to disk-like storage media, like hard-disks, CDs, DVDs, etc

Ram

RAM (Random Access Memory) is a form of computer data storage

System mb potential

Quality Example
Slower

"Once you re out of ram and the system starts swapping - disk access is thousands times slower than ram so any potential benefits of 64-bit code are flying out of window"

from question "32bit Operating systems vs 64 bit operating system"

"In other words the operating system is using some of your hard disk space to satisfy your 13 mb allocation request at great expense of speed since the hard disk is much much slower than ram"

from question "Malloc allocates memory more than RAM"

Swap processes fragmentation

Quality Example
Larger

"It uses swap space on disk to allow for processes much larger than ram"

from question "Malloc Memory Consumption Behavior in C"

System page operating

Quality Example
Slower system

"There exist battery-backed packages of ram modules which can act as an ultra-fast hdd substitute but if they attach via sata scsi or other typical disk interface the still are slower than system ram"

from question "Programming in the era of SSD"

Slower

"This is slow because your hard disk is significantly slower than ram and at 7gb there will be a lot of data being read from your hard disk put into ram then moved back to your page file the file on disk your operating system uses to store data that has been copied out of ram"

from question "Reading a big text file and memory"

Smaller time table

Quality Example
Larger

"This is well within disk space but far larger than ram"

from question "How to import a gzip file larger than RAM limit into a Pandas DataFrame? "Kill 9" Use HDF5?"

Bigger

"The table on disk is bigger than your ram"

from question "SELECT on 80 Million rows taking too long"

Smaller

"So even if your ram is much smaller than your disk you could assume you can read data that s already in ram 90 of the time or more"

from question "What does it mean for a MySQL table to fit in main memory?"

Cheaper storage persistence

Quality Example
Cheaper

"Disk space is probably always going to be cheaper than ram"

from question "Is Virtual Memory still relevant in today's world of inexpensive RAM?"

More

"Basically ram is more expensive than the disk storage"

from question "Hadoop, hardware and bioinformatics"

Space cheaper

"This approach will radically reduce heap space usage - disk space is cheaper then ram too"

from question "XPages: Too many instances of Java classes causing java/lang/OutOfMemoryError"

Storage cheaper

"Always favor disk persistence disk storage is cheaper than ram"

from question "Best setting for HTTPJVMMaxHeapSize in Domino 8.5.3 64 Bit"

Ssd alot subsequent

Quality Example
Slower

"The first load involves reading alot from the hard disk which is slow even ssd is slower than ram subsequent loads should be faster though 3 seconds on the ssd seem to be odd"

from question "System's hardware requirements for Symfony2"

"Another option is to spend a bit of cash on a 15000 rpm disk or a ssd solid state disk although that ll be slower than a ram disk"

from question "Emulating a physical disk to speed up execution?"

Access

Quality Example
Access much more fast

"And ram access is much more fast than disk access"

from question "Python - running a program increasingly faster"

Less

"More ram means less disk access"

from question "Why is Available Physical Memory (dwAvailPhys) > Available Virtual Memory (dwAvailVirtual) in call GlobalMemoryStatus on Windows Vista x64"

Available larger varnish

Quality Example
Larger

"So while the writes my be sequential on disk for datasets larger than ram these random reads will quickly become the bottle neck"

from question "Sorted String Table (SSTable) or B+ Tree for a Database Index?"

Larger available

"In future these lists may be read from disk and larger than available ram"

from question "Joining a set of ordered-integer yielding Python iterators"

"It is needed for a lookup of repetitions in disk files much larger than available ram"

from question "Efficient 'rolling/moving hash' computation (like moving average)"

Faster seek nanoseconds

Quality Example
Read slower

"Pros of objects faster disk read is slower than ram lesser dependencies of the system s state"

from question "Which is better approach between holding object in memory or storing data in some file/database"

Slower

"A disk seek takes about 10 000 000 nanoseconds of course some disk are faster but the best of them are still thousands of times slower than ram"

from question "What does it mean for a MySQL table to fit in main memory?"

4gb enough jboss

Quality Example
More enough

"This particular jboss runs in a vm with 4gb of ram and 2 cpu s and more than enough disk space it has never has less than 5gb free at any time"

from question "NoClassDefFoundError on JBoss5"

"For this reason i deployed a 2 cores 4gb ram and more than enough disk to run through the getting started example of the enterprise integrator"

from question "* (no title is found for this review)"

Data machine expensive

Quality Example
More expensive

"But ram is volatile the data in ram is erased when the computer loses power and ram is far more expensive than disk per unit of storage"

from question "What does it mean for a MySQL table to fit in main memory?"

More important

"If the hot data won t fit in ram on either machine then disk i o performance becomes more important than ram mostly random read i o and the fsync flush rate"

from question "Heroku PostgreSQL Crane DB vs Linode 1GB with PostgreSQL installed"

Much slower

"Reloading pages data or program code from disk which is much slower does not usually happen very often as long as the program is actually running and as long as the machine is not desperately low on ram"

from question "Run program from RAM on Windows"

Faster slower memory

Quality Example
Faster

"Ram is always faster than disk"

from question "Php cache class?"

"For this reason it seemed natural to me to initially load the file into memory and interpret it later at my leisure since reading from ram is supposed to be much faster than from disk"

from question "Working with binary files in MATLAB: load as-is to memory and interpret later"

"Ram is much faster than disk"

from question "Running a managed application 2nd time shows different performance than 1st"

"Loosely speaking ram is 1000 or more times faster than disk and cpu is faster still"

from question "What is the Fastest Method for High Performance Sequential File I/O in C++?"

"No trivial support for cache accessing ram is faster than accessing disk"

from question "Would implementing files (all types: audio, video, text, etc.) as database tables and their content as their rows be worthwile?"

"1 yes there is a obvious benefit reading from ram is faster than reading from disk"

from question "Is there any advantages in serving files from a massive object instead of from a hard drive in Node.JS"

"I understand that ram is typically thousands of times faster than disk but i o speed is not the only code running"

from question "Will this result in two full table scans?"

"Ram is a lot faster than disk"

from question "Database performance checklist"

Slower

"So even ignoring practical considerations like disk is slower than ram it will be slower"

from question "Lucene performance impact of returning large result sets"

"The initial read has to access the disk which is a lot slower than accessing ram"

from question "Understanding performance of numpy memmap"

"Disk io - even ssd - is many orders of magnitude slower than the ram that the hashing is going though"

from question "How much more likely are hash collisions if I hash a bunch of hashes?"

"That means that without caching a hit against disk will be 200 times slower than accessing ram"

from question "ASP.NET: are aspx/ascx files accessed from disk on every request?"

"Ssd disk are good but they are still much slower than ram"

from question "How do I know if MongoDB needs more CPU/RAM?"

"As disk is 1000s of times slower than ram this problem can grind the machine down to a practical halt"

from question "Malloc() inside an infinte loop"

"Disk even ssd are orders of magnitude slower than ram"

from question "Can a Nodejs process uses more memory than the available physical memory (by using swap memory)?"

"This is relatively slow since reading from the hard disk is slower than reading from ram"

from question "Why my WPF application becomes slow after a while of minimizing?"

"If too much memory is consumed it might swap to disk which is slower than ram"

from question "Scrapy spiders drastically slows down while running on AWS EC2"

"Which will lead to performance issue all programs will be work slower because read info from disk is slower than from ram"

from question "When OS using hard disk as additional disk space?"

"Disk i o is about 100 000 times slower than ram"

from question "MySQL LIMIT x,y performance huge difference on 2 machine"

"Disk access is much slower than ram"

from question "What are the bottlenecks inherent in networking?"

"Remember disk is 1000s of times slower than ram"

from question "Java web application really slow"

"Anyway you will have a huge performance loss due to the fact that your disk is way slower than your ram"

from question "Allocating aligned memory for larger arrays"

"Disk io will be slower than ram"

from question "Best practice session management on Amazon Platform"

"I think it is because the disk is slower than ram"

from question "Hybrid in Memory database SQLite"

"If the worker processes do other things than just calulations read from or write to disk they will have to wait a lot since a disk is a lot slower than ram"

from question "Understanding the usage of cpu cores of the multiprocessing module"

"Run the following to sort the data on disk this is slower than pulling it into ram sorting and then writing to disk"

from question "How to correctly partition a table in real-time in kdb?"

"Disk is 100x slower than ram"

from question "C++ extincting features"

Much faster

"Obviously reading a block from cache is much more efficient than reading it off the disk since ram is much faster than disk"

from question "Fine tuning oracle query with pipelined function"

"The ram is much faster than the hard disk"

from question "Need help understanding basic computer architecture"

Much slower

"Changing it will require a reboot. that will slow things down a bit as the swap file on disk is much slower than ram"

from question "Java Out of memory heapspace"

"As you run queries it has to fetch data from disk which is much slower than ram"

from question "MySQL fetch time issue"

Io way slower

"But you should consider that disk io is way slower than ram"

from question "Writing an entire list to a file in java"

Much slower then

"Only one disk read - since the disk is much slower then ram -"

from question "How to get the Top 10 from a huge amount data divided in 10 files like the formal of key->value_count?"

Others

Quality Example
Alway faster

"Buy as much memory as you can afford ram is alway faster than io from disk"

from question "Setup tips for installing a new SQL Server Database"

Bigger

"Disk is bigger than ram"

from question "Storing Large Lookup Tables"

Faster

"I would say that probably yes as long as we have enough of ram which is faster that virtual memory in case we need to access something from the disk which is extremely slow... but also i know that some applications just require having paging"

from question "Any type of system would be beneficial not to have a virtual memory"

"Ram is a lot faster than disk so reads and writes are temporarily stored until the data is requested by the code or the disk is able to receive it"

from question "Odd Ruby output lag under nohup?"

"So my question is how to move this database into ram where i can access it via sqlite3_open or if my idea is bullshit and leaving the database on disk is faster than moving it into ram via mapping"

from question "Moving SQL Database into ram"

"Since using ram is faster than using disk zram allows linux to make more use of ram when swapping paging is required especially on older computers with less ram installed"

from question "Difference between ZRAM and ZSWAP"

Slower

"There are libraries that allow on-disk data structures comes to mind and another one whose name i can t recall at the moment but disk accesses are orders of magnitude slower than ram"

from question "How can I initialize 2D array of huge size 1000000x1000000?"

"Caching and buffering are quite important since disk are just so much slower than ram and ram is much slower than the cpu"

from question "Text file not updating right away when using TextWriter"

"If lob-storage isn t in ram at the time of a query execution then we need to read it from a disk which is of course much slower than from ram"

from question "Adding datalength condition makes query slow"

"However be aware of this to cache pixels to disk is several orders of magnitude slower than using ram"

from question "* (no title is found for this review)"

"Make sure you have enough ram so that your data set fits with ram atleast your index should fit inside the ram coz each time a data fetched from disk is 10 times slower than ram"

from question "How to improve the performance of feed system using mongodb"

"Or if there is too much intermediate output to be shuffled your job will become slow as you will need disk based shuffle in such a case which will be slower than ram based shuffle"

from question "How to tune mapred.reduce.parallel.copies?"

"It won t do anything to change the fact that disk io is orders of magnitude slower than ram"

from question "Split up db tables to balance load?"

"As sven marnach wrote in the comments your problem is most likely i o bound since disk access is orders of magnitude slower than ram access"

from question "Efficient Matrix-Vector Multiplication: Multithreading directly in Python vs. using ctypes to bind a multithreaded C function"

"Disk files are of course an order of magnitude slower than ram and thrashing your virtual memory system could actually be worse than that depending on your access patterns"

from question "Linear regression in NumPy with very large matrices - how to save memory?"

"Since your disk even if it s an ssd is several orders of magnitude slower than ram the systems gets unresponsive"

from question "Pc going unresponsive when looping over a 10^8 elements in an array"

"Memory is a bottleneck to performance ram runs slower than the cpu and if you re paging to disk than it s really slow"

from question "Funny enough,this is probably a stack overflow problem"

"That s basically possible but it would take hours as hard disk access is so much slower than accessing ram caches"

from question "Is there any way to rotate an Image on Android without loading whole image to the memory?"

Less

"Any db tech is fine with me as long it does not need lots of ram and uses less disk"

from question "Most space efficient way to store 200 million records?"

"And at worst impossible at all ram size is usually much less than disk size"

from question "Understanding file pointers and buffers"

"If the amount of ram is less you ll have a lot of swapping to disk which is a lot more time consuming"

from question "Using Parallel::ForkManager to process file"

Io extremely slower then

"When the data is in memory - you can do anything much faster on it since disk io is extremely slower then ram so sorting it and reading it multiple times is expected to be much slower then manipulating the data on memory"

from question "How to get the Top 10 from a huge amount data divided in 10 files like the formal of key->value_count?"

More space

"Data in ram can take a lot more space than on disk"

from question "Pandas error while reading 14 GB csv file on 200 GB RAM workstation"

Usually faster

"But becuase reading from ram is usually faster than from other kind of memory storage divice os copy the program from disk on ram and start executing program from there"

from question "Relocation task"

Access much slower

"Using multiprocessing is probably not going to speed up reading data from disk since disk access is much slower than ram access or calculations"

from question "Multiprocessing in python, multiple process running same instructions"

Bandwidth much higher

"Also ram bandwidth is much higher than disk or ssd or network bandwidth and the ram latency is much lower too"

from question "How to search and replace a string in a file C"

Much faster

"Just wanted to weigh in my two cents what serialworm and thephpdeveloper said share the fact that memory ram is much faster than any disk io bound operation you come up with"

from question "PHP - Is it good practice to cache MYSQL queries in a txt file?"

"Accessing the main memory ram is much faster than reading values from the hard disk"

from question "Shared hit cache in postgreSQL"

"Reading audio files from ram is much faster than reading audio files from hard disk"

from question "Keeping audio clips in memory"

"The idea is to get the library and application loaded from ram into ram which is much faster than loading from disk"

from question "(qt/embedded) How to load a library before running the program"

Greater available

"Also keep in mind that once ram is exhausted your program will start running in virtual memory on disk which will probably cause far more disk i o activity than the program itself so if you re concerned about disk i o your best bet is probably to make sure that the batch of data you re working on in memory doesn t get much greater than available ram"

from question "Minimising reading from and writing to disk in Python for a memory-heavy operation"

Slower cpu

"Query speed is mainly limited by disk i o speed which is at least 1000 times slower than cpu ram speed"

from question "Reason for different SQL performances for same code on identical servers"

Always faster

"Saving information to a variable and therefore to ram is always faster than direct to disk"

from question "Which is more efficient, storing output in variable or output to file?"

"For the stand of file operations writing to memory ram is always faster than writing to the file on the disk directly"

from question "Why is buffering in C++ important?"

Slower memory

"Because hard disk have a much slower memory than ram virtual private server performance may slow down considerably"

from question "Memory usage issues with VPS (ubuntu): MySQL process dies"

Vastly slower

"Remember the tuples are saved into the disk which is vastly slower to access than things in ram"

from question "Jquery JSON array as localStorage item"

Access much slower then

"However if this is indeed the case - and the data does not fit ram and you cannot use map-reduce i suspect sorting and iterating - though will be o nlogn will be more efficient using external sort - because the number of disk accesses will be minimized and disk access is much slower then ram access"

from question "Find most frequent elements in set"

Memory faster

"We all know that the access to ram memory is faster than access to hard disk"

from question "Is it possible to save hexadecimal code of image files in RAM via clipboard?"

Access much more

"I m sure there are other holes like that too - but the code above will work on any system which supports paging and where disk access is much more expensive than ram access"

from question "How to get page size"

Smaller

"In this case the latter is likely to cause trouble because the insertion of a name hits a random node in the tree i.e the name insertion doesn t follow a pattern and your ram is smaller than the index chances are high that the destination must be fetched from disk"

from question "MongoDB insert performance with 2nd index"

Typically more expensive

"However they may be cheaper to operate depending on how much data you are expecting to store with each session key holding large quantities of data in ram is typically more expensive than storing on disk"

from question "Storing userdata in $_SESSION vs. repeated DB accesses"

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