#108: Nastran Memory Settings<\/p>\n
Memory is allocated on the MEM parameter. The MEM parameter cannot exceed memorymax. memorymax defaults to 50% of RAM and should not exceed 80% of physical RAM. It may be redefined on the command line or the RC file. The memory used by the solver can be seen in the F04 file:<\/p>\n
For example,
\nMINIMUM MEMORY REQUIREMENT = 47039 K WORDS
\nMEMORY AVAILABLE = 831121 K WORDS
\nMEMORY REQR’D TO AVOID SPILL = 47302 K WORDS<\/p>\n
mem=10gb (value)
\nmem=24gb
\nmem=0.8xphysical (percent of physical)
\nmem=max (for SOL 101 and 400 estimated amount of memory will go to the solver and the rest will go to BPOOL, if not SOL 101 or 400 the solver gets 75% and BPOOL gets 25% of memorymax)<\/p>\n
More RAM is always better.
\nThe RAM is used for the Nastran Solver and executive sections as well as for a computer’s cache. More RAM allows for a greater amount of BUFFPOOL.<\/p>\n
MEMORYMAX is the amount of memory allowed to MSC Nastran during the analysis. MEMORYMAX is partitioned off or the sum of various chunks: USER OPENCORE (HICORE), EXECUTIVE SYSTEM WORK AREA, etc. Part of MEMORYMAX is used for BPOOL (BUFFER POOL AREA). This memory is used for the DBSET FILES.<\/p>\n
MSC Nastran automatically sets MEMORYMAX and BPOOL. By default, MSC Nastran sets MEMORYMAX to 50% of you systems memory and BPOOL to 25% of MEMORYMAX. For example, my laptop has 16GB of RAM, then MEMORYMAX=8GB and BPOOL=2GB.<\/p>\n
1) Make sure that USER OPENCORE (HICORE) \u2248 MEMORY AVAILABLE is greater than MEMORY REQR’D TO AVOID SPILL. These two values are found in the .f04 file. To increase USER OPENCORE (HICORE) simply specify a higher MEMORYMAX in the command line, assuming every other memory setting is held constant. For example, if before you specified MEMORYMAX=5GB and then, MEMORYMAX=10GB, you will find an increase in USER OPENCORE (HICORE).<\/p>\n
2) Make sure the Buffer Pool supplied is greater than the sum of HIWATER of DBSET FILES. To increase Buffer Pool, simply specify a higher BPOOL in the command line. For example, when I look at the .f04 file, see Figure , I see there is a total of about 8GB \u2248 .039+.022+.006+6.715+1.256. I should use a BPOOL of 8GB. If I have to increase BPOOL, I should also increase MEMORYMAX appropriately. Remember that BPOOL is a portion of MEMORYMAX.
\nBefore: MEMORYMAX=8GB BPOOL=2GB SCR=YES
\nAfter: MEMORYMAX=10GB BPOOL=8GB SCR=YES<\/p>\n
I can specify SMP=4 in MSC Nastran command line and utilize all 4 cores for the analysis<\/p>\n
For solid element models, use the CASI Solver The model I am doing the benchmark is comprised of solid elements. MSC Nastran includes an iterative solver named CASI and should be used for solid element models. To use this solver, add “smethod=element” to the case control section of the .bdf\/.dat file.<\/p>\n
MEM=4GB SMEM=2GB PARALLEL=3<\/p>\n
mem=max<\/p>\n","protected":false},"excerpt":{"rendered":"
#108: Nastran Memory Settings Memory is allocated on the MEM parameter. The MEM parameter cannot exceed memorymax. memorymax defaults to 50% of RAM and should not exceed 80% of physical RAM. It may be redefined on the command line or the RC file. The memory used by the solver can be seen in the F04 […]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"nf_dc_page":"","_et_pb_use_builder":"","_et_pb_old_content":"","_et_gb_content_width":"","_lmt_disableupdate":"yes","_lmt_disable":"","jetpack_post_was_ever_published":false,"_jetpack_newsletter_access":"","_jetpack_dont_email_post_to_subs":false,"_jetpack_newsletter_tier_id":0,"_jetpack_memberships_contains_paywalled_content":false,"_jetpack_memberships_contains_paid_content":false,"footnotes":""},"categories":[22],"tags":[],"class_list":["post-657","post","type-post","status-publish","format-standard","hentry","category-nastran"],"modified_by":"gantovnik","jetpack_featured_media_url":"","jetpack_sharing_enabled":true,"jetpack_shortlink":"https:\/\/wp.me\/p8bH0k-aB","jetpack_likes_enabled":true,"jetpack-related-posts":[{"id":1095,"url":"https:\/\/gantovnik.com\/bio-tips\/2021\/11\/190-run-options-for-optistruct\/","url_meta":{"origin":657,"position":0},"title":"#190 Run options for OptiStruct","author":"gantovnik","date":"2021-11-13","format":false,"excerpt":"List of possible run options for OptiStrut -analysis | submit an analysis run. Check the optimization data. -optskip | submit an analysis run without optimization. -check | submit a check job through the command line. -nt X | number of threads\/cores (X) to be used for multiprocessor (SMP) run. -np\u2026","rel":"","context":"In "OptiStruct"","block_context":{"text":"OptiStruct","link":"https:\/\/gantovnik.com\/bio-tips\/category\/optistruct\/"},"img":{"alt_text":"","src":"","width":0,"height":0},"classes":[]},{"id":688,"url":"https:\/\/gantovnik.com\/bio-tips\/2020\/09\/121-windows-batch-script-to-run-every-nastran-input-file-in-folder\/","url_meta":{"origin":657,"position":1},"title":"#121: Windows batch script to run every Nastran input file in folder","author":"gantovnik","date":"2020-09-28","format":false,"excerpt":"This is an example of a Windows bat file to run Nastran for every *.dat file in the current folder. It also calculates the total Nastran execution time. Of course, you should change the path to nastran.exe. 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SOL 400\u2026","rel":"","context":"In "buckling"","block_context":{"text":"buckling","link":"https:\/\/gantovnik.com\/bio-tips\/category\/buckling\/"},"img":{"alt_text":"","src":"","width":0,"height":0},"classes":[]},{"id":673,"url":"https:\/\/gantovnik.com\/bio-tips\/2020\/09\/115-rbe3-vs-rbe2\/","url_meta":{"origin":657,"position":3},"title":"#115 Nastran Tips: When to Use RBE2 vs. RBE3 Elements","author":"gantovnik","date":"2020-09-28","format":false,"excerpt":"#115: RBE3 and RBE2 RBE2 (Rigid Body Element Type 2): Represents an infinitely stiff connection. All connected nodes (slave nodes) follow the exact same translations and rotations as the master node. There is no relative motion between the master and slave nodes. Commonly used for rigid body constraints, fixtures, or\u2026","rel":"","context":"In "nastran"","block_context":{"text":"nastran","link":"https:\/\/gantovnik.com\/bio-tips\/category\/nastran\/"},"img":{"alt_text":"","src":"","width":0,"height":0},"classes":[]},{"id":1809,"url":"https:\/\/gantovnik.com\/bio-tips\/2023\/03\/342-gravity-loading-in-nastran-grav-card\/","url_meta":{"origin":657,"position":4},"title":"#342 Gravity loading in Nastran (GRAV card)","author":"gantovnik","date":"2023-03-09","format":false,"excerpt":"Inertia loading: 1G GRAV load (down) Description: Used to define gravity vectors to determine gravity loading for the structural model. SID = load id. CID = coordinate system id. A CID=0 references the basic coordinate system. If CID=-1, the gravity vector components are in the local displacement coordinate system of\u2026","rel":"","context":"In "nastran"","block_context":{"text":"nastran","link":"https:\/\/gantovnik.com\/bio-tips\/category\/nastran\/"},"img":{"alt_text":"","src":"","width":0,"height":0},"classes":[]},{"id":900,"url":"https:\/\/gantovnik.com\/bio-tips\/2021\/02\/162-loops-using-command-line-in-bash\/","url_meta":{"origin":657,"position":5},"title":"#162 Loops using command line in bash","author":"gantovnik","date":"2021-02-19","format":false,"excerpt":"With increment: Output: Output: C-like syntax: Output: Output: Output: Output: Output: Output:","rel":"","context":"In "bash"","block_context":{"text":"bash","link":"https:\/\/gantovnik.com\/bio-tips\/category\/bash\/"},"img":{"alt_text":"","src":"","width":0,"height":0},"classes":[]}],"_links":{"self":[{"href":"https:\/\/gantovnik.com\/bio-tips\/wp-json\/wp\/v2\/posts\/657","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/gantovnik.com\/bio-tips\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/gantovnik.com\/bio-tips\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/gantovnik.com\/bio-tips\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/gantovnik.com\/bio-tips\/wp-json\/wp\/v2\/comments?post=657"}],"version-history":[{"count":0,"href":"https:\/\/gantovnik.com\/bio-tips\/wp-json\/wp\/v2\/posts\/657\/revisions"}],"wp:attachment":[{"href":"https:\/\/gantovnik.com\/bio-tips\/wp-json\/wp\/v2\/media?parent=657"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/gantovnik.com\/bio-tips\/wp-json\/wp\/v2\/categories?post=657"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/gantovnik.com\/bio-tips\/wp-json\/wp\/v2\/tags?post=657"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}