Kingston DC500R Solid State SSD Review rau Enterprise Cov neeg siv

Kingston tsis ntev los no tso tawm kev lag luam SSD Kingston DC 500R, tsim rau siab loads tas li. Tam sim no ntau tus neeg sau xov xwm nquag sim cov khoom tshiab thiab tsim cov ntaub ntawv nthuav dav. Peb xav qhia rau Habr ib qho ntawm peb cov lus qhia ntxaws ntxaws ntawm Kingston DC500R, uas cov neeg nyeem yuav txaus siab rau kev sim. Tus thawj yog nyob rau ntawm lub website Kev tshuaj xyuas cia thiab luam tawm ua lus Askiv. Rau koj txoj kev yooj yim, peb tau txhais cov ntaub ntawv ua lus Lavxias thiab muab tso rau hauv qab txiav. Txaus siab rau kev nyeem ntawv!

Kingston DC500R Solid State SSD Review rau Enterprise Cov neeg siv

Cov khoom siv cia Kingston DC 500R tsim raws li 3D TLC NAND flash nco tshuab. Muaj nyob rau hauv lub peev xwm ntawm 480GB, 960GB, 1,92TB thiab 3,84TB, muab kev xaiv ntxiv rau cov lag luam nrhiav kev txuag nyiaj lossis cov uas tsuas yog tsis xav tau lub peev xwm siab. Qhov kev tshuaj xyuas no tsom mus rau 3,48 TB variant, uas tau thov kev nyeem thiab sau nrawm ntawm 555 MB / s thiab 520 MB / s, raws li, thiab 4 KB thaiv kev nyeem thiab sau nrawm raws li kev txhawb nqa ntawm 98 thiab 000 IOPS - tso zis ib ob (IOPS), raws. Raws li ib feem ntawm tsev neeg cov khoom no, Kingston kuj muaj DC28M, uas yog qhov zoo rau kev siv sib xyaw.

Kingston DC500R Solid State SSD Review rau Enterprise Cov neeg siv

Kingston DC500R Solid State SSD Review rau Enterprise Cov neeg siv

Kingston DC500R Specifications

Kingston DC500R Solid State SSD Review rau Enterprise Cov neeg siv

Tsim tau

Kev Ntsuam Xyuas
Lub kaw lus tau siv los ntsuas kev lag luam SSDs nrog cov ntawv thov tiag tiag hauv ntiaj teb. Lenovo ThinkSystem SR850, thiab rau kev kuaj hluavtaws - Dell PowerEdge R740xd. Lub ThinkSystem SR850 yog qhov ua kom zoo tshaj plaws quad-core platform uas xa cov kev ua haujlwm ntau dua li qhov xav tau los ntsuas qhov ua tau zoo hauv zos cia. Rau kev ntsuam xyuas hluavtaws, qhov twg CPU muaj peev xwm tsis tseem ceeb, ib txwm siv ntau lub server nrog ob lub processors. Hauv ob qho xwm txheej, peb cia siab tias yuav ua tiav qhov kev cia khoom hauv zos uas phim cov neeg tsim khoom thov.

Lenovo ThinkSystem SR850

  • 4 Intel Platinum 8160 processors (2,1 GHz, 24 cores)
  • 16 DDR4 ECC DRAM nco modules nrog zaus ntawm 2666 MHz nrog lub peev xwm ntawm 32 GB txhua
  • 2 RAID 930-8i 12 Gbps adapters
  • 8 NVMe tsav
  • VMware ESXI 6.5 software

Dell PowerEdge R740xd

  • 2 Intel Gold 6130 processors (2,1 GHz, 16 cores)
  • 4 DDR4 ECC DRAM nco modules nrog zaus ntawm 2666 MHz nrog lub peev xwm ntawm 16 GB txhua
  • RAID adapter PERC 730, 12 Gbps, 2 GB tsis
  • Embedded NVMe adapter
  • OS Ubuntu-16.04.3-desktop-amd64

Kingston DC500R Solid State SSD Review rau Enterprise Cov neeg siv

Cov ntaub ntawv xeem

StorageReview Enterprise Test Lab muab ntau lub sijhawm los sim cov cuab yeej cia hauv ib puag ncig ze rau lub ntiaj teb tiag tiag. Lub chaw soj nstuam suav nrog ntau lub servers, cov khoom siv network, lub zog hluav taws xob thiab lwm yam kev tsim kho hauv network. Qhov no tso cai rau peb cov neeg ua haujlwm tsim cov xwm txheej tiag tiag los ntsuas cov cuab yeej ua haujlwm tau zoo.
Cov ntaub ntawv ib puag ncig thiab cov txheej txheem tau suav nrog hauv kev tshuaj xyuas kom IT thiab cov neeg ua haujlwm khaws cia tuaj yeem ntsuas cov xwm txheej raws li cov txiaj ntsig tau ua tiav. Cov neeg tsim khoom ntawm cov khoom siv nyob rau hauv kev sim tsis them nyiaj rau lossis tswj kev tshuaj xyuas.

Daim ntawv thov ua haujlwm tsom xam

Txhawm rau ntsuas kev ua lag luam khaws cia cov cuab yeej ua haujlwm tau zoo, nws yog ib qho tseem ceeb uas yuav tsum ua qauv rau koj cov kev tsim kho vaj tse thiab cov ntawv thov ua haujlwm kom haum rau koj qhov chaw nyob hauv ntiaj teb. Yog li, txhawm rau ntsuas Samsung 883 DCT SSDs, peb ntsuas MySQL OLTP database kev ua tau zoo siv SysBench utility и Microsoft SQL Server OLTP database kev ua tau zoo siv TCP-C workload emulation. Nyob rau hauv cov ntaub ntawv no, rau daim ntawv thov, txhua tsav yuav lis 2 mus rau 4 tus kheej configured virtual machines.

SQL Server Performance

Txhua SQL Server virtual tshuab tau teeb tsa nrog ob lub virtual disks: 100 GB khau raj disk thiab 500 GB disk rau khaws cov ntaub ntawv thiab cov ntaub ntawv teev cia. Hais txog cov kev pab cuam, txhua lub tshuab virtual tau nruab nrog 16 virtual processors, 64 GB ntawm DRAM, thiab SAS SCSI maub los ntawm LSI Logic. Peb yav dhau los tau sim I / O kev ua tau zoo thiab kev cia khoom siv Sysbench workloads. SQL xeem, nyob rau hauv lem, pab kwv yees latency.

Raws li ib feem ntawm kev sim, SQL Server 2014 yog siv rau ntawm cov qhua virtual tshuab khiav Windows Server 2012 R2. Loads yog tsim siv Benchmark Hoobkas rau Databases software los ntawm Quest. Microsoft SQL Server OLTP Database Testing Protocol StorageReview siv cov qauv tam sim no ntawm Kev Ua Haujlwm Kev Ua Haujlwm Pabcuam Kev Ua Haujlwm ntawm Benchmark C (TPC-C) software. Qhov no real-time kev lag luam kev ua tau zoo benchmark simulates cov txheej txheem ntawm complex daim ntawv thov ib puag ncig. Kev ntsuas TPC-C tuaj yeem txheeb xyuas qhov ua tau zoo thiab qhov tsis muaj zog ntawm cov khoom siv hauv cov chaw khaws ntaub ntawv ntau dua li kev ntsuas kev ua tau zoo. Hauv peb qhov kev sim, txhua qhov SQL Server VM piv txwv tau khiav 333 GB (1500 nplai) SQL Server database. Kev ua tau zoo thiab kev ntsuas latency rau kev ua lag luam tau ua raws li kev thauj khoom ntawm 15000 tus neeg siv virtual.

SQL Server test configuration (ib VM):
• Windows Server 2012 R2
• Disk qhov chaw: 600 GB faib, 500 GB siv
• SQL Server 2014
- Database loj: 1 teev
- Tus naj npawb ntawm cov neeg siv khoom virtual: 15
- RAM nco tsis: 48 GB
• Lub sijhawm kuaj: 3 teev
- 2,5 teev - theem ua ntej
— 30 ​​feeb — kev ntsuam xyuas ncaj qha

Raws li SQL Server kev ua haujlwm kev ua haujlwm, Kingston DC500R tsuas yog me ntsis tom qab Samsung 883 DCT, nrog rau tag nrho kev ua tau zoo ntawm 6290,6 kev lag luam ib ob (TPS).

Kingston DC500R Solid State SSD Review rau Enterprise Cov neeg siv

Ib txoj hauv kev zoo dua los ntsuas SQL Server kev ua tau zoo dua li TPS yog los ntawm kev ntsuas qib latency. Ntawm no, ob qho tib si tsav - Samsung 860 DCT thiab Kingston DC500R - pom tib lub sijhawm: 26,5 ms.

Kingston DC500R Solid State SSD Review rau Enterprise Cov neeg siv

Kev ua tau zoo thaum siv Sysbench

Cov kev sim hauv qab no tau siv cov ntaub ntawv Percona MySQL. OLTP kev ua tau zoo tau raug soj ntsuam siv SysBench qhov hluav taws xob. Qhov no ntsuas qhov nruab nrab TPS thiab latency, nrog rau qhov nruab nrab latency nyob rau hauv qhov xwm txheej phem tshaj plaws.

Txhua lub tshuab virtual sib Kuv siv peb lub virtual disks: khau raj disk nrog lub peev xwm ntawm 92 GB, ib lub disk nrog cov ntaub ntawv khaws cia ua ntej nrog lub peev xwm ntawm 447 GB, thiab lub disk nrog cov ntaub ntawv ntsuas nrog lub peev xwm ntawm 270 GB. Hais txog cov kev pab cuam, txhua lub tshuab virtual tau nruab nrog 16 virtual processors, 60 GB ntawm DRAM, thiab SAS SCSI maub los ntawm LSI Logic.

Sysbench test configuration (ib VM):

• CentOS 6.3 64-ntsis
• Percona XtraDB 5.5.30-rel30.1
- Tus lej ntawm cov ntaub ntawv: 100
- Database loj: 10
- Number of database threads: 32
- RAM nco tsis: 24 GB
• Lub sijhawm kuaj: 3 teev
- 2 teev - theem ua ntej, 32 ntws
- 1 teev - kuaj ncaj qha, 32 xov

Sysbench qhov kev hloov pauv kev ua tau zoo ntawm kev ua tau zoo ua rau DC500R tom qab kev sib tw nrog 1680,47 kev lag luam ib ob.

Kingston DC500R Solid State SSD Review rau Enterprise Cov neeg siv

Nyob rau hauv cov nqe lus ntawm qhov nruab nrab latency, DC500R kuj ranked kawg nrog 76,2 ms.

Kingston DC500R Solid State SSD Review rau Enterprise Cov neeg siv

Thaum kawg, tom qab kuaj latency nyob rau hauv qhov xwm txheej phem tshaj plaws (99th feem pua), DC500R tau rov qab rau hauv qab ntawm daim ntawv teev npe nrog tus qhab nia ntawm 134,9ms.

Kingston DC500R Solid State SSD Review rau Enterprise Cov neeg siv

VDBench Workload Analysis

Thaum kuaj cov cuab yeej khaws cia, kev sim raws li daim ntawv thov yog nyiam dua cov kev sim hluavtaws. Txawm li cas los xij, txawm hais tias lawv cov txiaj ntsig tsis sib haum rau cov xwm txheej hauv ntiaj teb tiag tiag, kev sim tshuaj hluavtaws, vim yog qhov rov ua haujlwm ntawm kev ua haujlwm, muaj txiaj ntsig zoo rau kev tsim cov hauv paus ntsiab lus thiab sib piv cov kev daws teeb meem sib tw. Cov kev ntsuam xyuas no muaj ntau yam ntawm cov ntaub ntawv - los ntawm plaub lub ces kaum kev xeem thiab cov kev ntsuam xyuas kev tsiv teb tsaws chaw mus rau kev taug qab ntes los ntawm ntau qhov chaw VDI. Tag nrho cov no siv ib zaug vdBench workload generator nrog ib tsab ntawv cav rau automate thiab aggregate cov qhabnias nyob rau hauv ib tug loj pawg ntawm xam. Qhov no ua rau nws muaj peev xwm siv tib lub zog ua haujlwm thoob plaws ntau yam ntawm cov drives, suav nrog tag nrho-flash arrays thiab ib tus neeg tsav tsheb. Raws li ib feem ntawm kev sim, peb tau sau tag nrho cov tsav nrog cov ntaub ntawv, thiab tom qab ntawd faib lawv mus rau hauv ntu nrog lub peev xwm ntawm 25% ntawm qhov qub los simulate daim ntawv thov loads thiab ntsuas tus cwj pwm ntawm tus tsav. Txoj hauv kev no txawv ntawm qhov kev xeem entropy tag nrho, uas siv tag nrho cov disk ib zaug nyob rau hauv tas li loads. Vim li no, cov txiaj ntsig hauv qab no qhia txog kev sau ntawv nrawm dua.

Profiles:
• 4 KB random nyeem: nyeem nkaus xwb, 128 xov, 0 txog 120% I/O ceev
• 4KB random sau: sau nkaus xwb, 64 threads, 0 txog 120% I/O ceev
• 64KB nyeem ib ntus: nyeem nkaus xwb, 128 xov, 0 txog 120% I/O ceev
• 64KB ib ntus sau: sau nkaus xwb, 64 xov, 0 txog 120% I/O ceev
• Synthetic databases: SQL thiab Oracle
• VDI daim ntawv luam (tag nrho cov ntawv luam thiab txuas txuas)

Hauv thawj VDBench (4KB Random Read) workload test, Kingston DC500R xa cov txiaj ntsig zoo, nrog latency nyob rau hauv 1 ms txog 80 IOPS thiab lub ncov ceev ntawm 000 IOPS ntawm 80 ms latency.

Kingston DC500R Solid State SSD Review rau Enterprise Cov neeg siv

Txhua qhov kev sim tsav tau pom yuav luag zoo ib yam hauv qhov kev sim thib ob (4 KB Random Sau): qhov nrawm me ntsis siab dua 63 IOPS nrog latency ntawm 000 ms.

Kingston DC500R Solid State SSD Review rau Enterprise Cov neeg siv

Tsiv mus rau cov haujlwm ua ntu zus, peb xub saib 64 KB nyeem. Nyob rau hauv rooj plaub no, Kingston tsav tau tswj xyuas sub-millisecond latency kom txog thaum ncav cuag 5200 IOPS (325 MB / s). Qhov siab tshaj plaws tus nqi ntawm 7183 IOPS (449 MB / s) nrog latency ntawm 2,22 ms coj qhov tsav no mus rau qhov chaw thib ob hauv tag nrho cov sawv cev.

Kingston DC500R Solid State SSD Review rau Enterprise Cov neeg siv

Thaum kuaj cov haujlwm sau ua ntu zus, Kingston ntaus ntawv ua tau zoo tshaj txhua tus neeg sib tw, ua kom qis qis qis dua 1 ms mus txog 5700 IOPS (356 MB / s). Qhov siab tshaj plaws ceev yog 6291 IOPS (395 MB / s) nrog latency ntawm 2,51 ms.

Kingston DC500R Solid State SSD Review rau Enterprise Cov neeg siv

Tom qab ntawd, peb tau tsiv mus rau SQL cov haujlwm, qhov twg Kingston DC500R tsav yog tib lub cuab yeej uas nws qib latency mus dhau ib millisecond hauv tag nrho peb qhov kev xeem. Hauv thawj kis, lub disk pom qhov siab tshaj plaws ntawm 26411 IOPS nrog latency ntawm 1,2 ms.

Kingston DC500R Solid State SSD Review rau Enterprise Cov neeg siv

Hauv kev xeem SQL 90-10, Kingston tsav tau dhau los nrog qhov siab tshaj plaws ntawm 27339 IOPS thiab latency ntawm 1,17 ms.

Kingston DC500R Solid State SSD Review rau Enterprise Cov neeg siv

Tib yam tshwm sim hauv SQL 80-20 xeem. Kingston ntaus ntawv nyob rau hauv cov ntaub ntawv no qhia ib tug siab tshaj plaws ceev ntawm 29576 IOPS nrog ib tug latency ntawm 1,08 ms.

Kingston DC500R Solid State SSD Review rau Enterprise Cov neeg siv

Oracle workload xeem tau ib zaug ntxiv muab tso rau DC500R nyob rau hauv qhov chaw kawg, tab sis lub cuab yeej tseem pom sub-millisecond latency nyob rau hauv ob qhov kev xeem. Hauv thawj kis, qhov siab tshaj plaws ceev ntawm Kingston disk yog 29098 IOPS nrog latency ntawm 1,18 ms.

Kingston DC500R Solid State SSD Review rau Enterprise Cov neeg siv

Hauv qhov kev sim thib ob (Oracle 90-10), DC500R ua tiav 24555 IOPS nrog latency ntawm 894,3 µs.

Kingston DC500R Solid State SSD Review rau Enterprise Cov neeg siv

Hauv qhov kev sim thib peb (Oracle 80-20), qhov siab tshaj plaws ntawm Kingston ntaus ntawv yog 26401 IOPS nrog rau qib latency ntawm 831,9 μs.

Kingston DC500R Solid State SSD Review rau Enterprise Cov neeg siv

Peb mam li txav mus rau VDI theej - tsim cov ntawv luam tag nrho thiab txuas. Hauv kev sim thauj cov ntaub ntawv VDI tag nrho, Kingston tsav rov ua tsis tau nws cov neeg sib tw. Cov cuab yeej tswj hwm latency qis dua 1 ms mus txog qhov nrawm ntawm 12000 IOPS, thiab qhov siab tshaj plaws yog 16203 IOPS nrog latency ntawm 2,14 ms.

Kingston DC500R Solid State SSD Review rau Enterprise Cov neeg siv

Thaum kuaj thawj tus ID nkag mus luam theej ntawm VDI, lub cuab yeej Kingston ua tau zoo dua, thaum kawg ua tiav (los ntawm me ntsis npoo) hauv qhov chaw thib ob. Tus tsav tswj tuav latency nyob rau hauv ib millisecond kom txog rau thaum mus txog speeds ntawm 11000 IOPS, thiab lub siab tshaj plaws ceev yog 13652 IOPS nrog ib tug latency ntawm 2,18 ms.

Kingston DC500R Solid State SSD Review rau Enterprise Cov neeg siv

Tsis tas li ntawd, los ntawm cov npoo me ntsis, Kingston tsav tau txais qhov thib ob hauv hnub Monday Login kuaj rau daim ntawv VDI tag nrho. Lub Seagate Nytro 1351 tsav muaj qhov siab dua me ntsis, tab sis Kingston ntaus ntawv tau qhia qis qis qis dua tag nrho thoob plaws qhov kev xeem. Qhov siab tshaj plaws ceev ntawm DC500R yog 11897 IOPS nrog latency ntawm 1,31 ms.

Kingston DC500R Solid State SSD Review rau Enterprise Cov neeg siv

Hauv kev sim thauj khoom txuas txuas VDI cov ntawv, Kingston ntaus ntawv tuaj rau qhov kawg. Lub latency mus dhau 1 ms twb nyob rau hauv speeds tsawg dua 6000 IOPS. Qhov siab tshaj plaws ceev ntawm DC500R yog 7861 IOPS nrog latency ntawm 2,03 ms.

Kingston DC500R Solid State SSD Review rau Enterprise Cov neeg siv

Txawm li cas los xij, raws li cov txiaj ntsig ntawm Kev Tshawb Fawb Kev Tshawb Fawb, kev tsav tsheb rov ua qhov thib ob: qhov latency tau dhau mus dhau ib millisecond tsuas yog tom qab yuav luag txog qhov ua tau zoo, uas thaum kawg suav txog 7950 IOPS nrog latency ntawm 1,001 ms.

Kingston DC500R Solid State SSD Review rau Enterprise Cov neeg siv

Hauv qhov kev sim tshiab kawg ntawm daim ntawv txuas ntawm VDI - Monday Login - tus tsav kuj pom qhov tshwm sim thib ob: qhov siab tshaj plaws ntawm 9205 IOPS nrog latency ntawm 1,72 ms. Qhov kev ncua mus dhau ib millisecond thaum qhov ceev mus txog 6400 IOPS.

Kingston DC500R Solid State SSD Review rau Enterprise Cov neeg siv

xaus

DC500R yog Kingston qhov tseeb SSD tsim rau cov neeg siv khoom lag luam. DC500R los hauv 2,5-nti daim ntawv zoo. Muaj peev xwm ntawm 480 GB txog 3,84 TB. Tus tsav yog ua raws li 3D TLC NAND flash nco thev naus laus zis thiab sib txuas cov peev txheej ntev thiab kev ua haujlwm siab. Rau 3,48 TB tsav, sib txuas nyeem thiab sau nrawm ntawm 555 thiab 520 MB / s tau teev tseg, raws li, nyeem thiab sau nrawm raws li qhov tsis tu ncua ntawm 98000 thiab 28000 IOPS, feem, nrog rau kev muaj peev xwm ntawm 3504 TBW.

Txhawm rau ntsuas qhov ua tau zoo ntawm Kingston DC500R, peb muab piv rau lwm qhov nrov SATA SSDs, suav nrog Samsung tsav. 860dct ua и 883dct ua, nrog rau kev khaws cia Seagate Nitro 3530 Nws. Kington DC500R muaj peev xwm ua tau raws li nws cov neeg sib tw, thiab qee zaum txawm tias dhau lawv. Thaum kuaj cov ntawv thov ua haujlwm, Kingston DC500R ua tau zoo thaum ua haujlwm SQL workloads, ua tiav thib ob tag nrho hauv kev lag luam ib ob (6291,8 TPS) thiab latency (26,5 ms). Hauv Sysbench qhov kev sim ntawm kev sau ntau cov haujlwm hnyav, DC500R tuaj rau hauv qab ntawm pob nrog cov qhab nia ua haujlwm ntawm 1680,5 TPS, qhov nruab nrab latency ntawm 76,2 ms, thiab qhov phem tshaj plaws latency ntawm 134,9 ms.

Hauv 4KB random nyeem thiab sau ntawv xeem, Kingston DC500R ua tiav 80209 IOPS thiab 1,59 ms nyeem latency, thiab 63000 IOPS thiab 2 ms sau latency. Hauv 64KB thaiv kev nyeem thiab sau ntawv, DC500R ua tiav qhov nrawm ntawm 7183 IOPS (449 MB / s) nrog 2,22 ms latency thiab 6291 IOPS (395 MB / s) nrog 2,51 ms latency, feem. Hauv kev sim hluavtaws siv SQL thiab Oracle databases thiab nce kev sau nrawm, DC500R qhov kev ua tau zoo tshuav ntau yam uas xav tau. Rau SQL workloads, Kingston DC500R tuaj nyob rau hauv tuag kawg nyob rau hauv tag nrho peb qhov kev xeem thiab yog tib tug tsav mus cuag sub-millisecond latency. Txawm li cas los xij, hauv kev sim Oracle daim duab tau ua kom zoo dua. Hauv ob ntawm peb qhov kev xeem, tus tsav tau tuav latency qis dua 1 ms, uas tau txais nws qhov thib ob. Kingston DC500R tau pom cov qib kev ua tau zoo thaum sim siv VDI cov ntawv luam, tag nrho thiab txuas.

Feem ntau Kingston DC500R SSD - cov cuab yeej zoo hauv nws cov chav kawm uas tsim nyog tau txais kev mloog zoo dua. Ntau npaum li peb nyiam cov thev naus laus zis ua tau zoo (NVMe thiab zoo sib xws), SATA drives tseem yog cov kev daws teeb meem zoo tshaj plaws rau kev ua haujlwm uas kev ntseeg siab yog qhov tseem ceeb, xws li khau raj lub server lossis chaw cia khoom. Cov tsav no kuj yog ib qho txiaj ntsig zoo rau kev khaws cov ntaub ntawv server hauv cov xwm txheej uas tus nqi ntawm cov nyiaj tseem ceeb. Lawv kuj muab tag nrho cov txiaj ntsig TCO uas teeb tsa SSDs sib nrug ntawm hard disk drives (HDDs). DC500R qhov kev ua tau zoo tso nws rau saum ntau ntawm peb qhov kev sim piv rau lwm cov tsav tsim nyog xav txog. DC500R yog qhov zoo tshaj plaws SATA tsav rau cov xwm txheej uas xav tau kev txhim khu kev qha, kev ua haujlwm siab nrog kev ua siab ntev thiab ntau yam muaj peev xwm.

DC500 series qauv muaj nyob rau hauv kev txiav txim los ntawm cov nom Kingston distributors.
Rau cov lus nug txog kev xeem thiab kev lees paub, koj tuaj yeem tiv tauj Kingston Technology tus neeg sawv cev hauv tebchaws Russia los ntawm e-mail [email tiv thaiv]

Yog xav paub ntxiv txog cov khoom Kingston Technology thov mus saib lub tuam txhab lub vev xaib.

Tau qhov twg los: www.hab.com

Ntxiv ib saib